View Full Version : Fuel Filter Test Results

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george morrison
10-25-2002, 20:28
Processed the disel fuel source and "after the filter" today and the results were not good. The "after the filter" results showed double the amount of abrasive particulates compared with the pump fuel that went into the truck's tank! We either had a defective fuel filter or possibly a mis-seated filter. The fuel filter had a little over 8,000 miles on it and the fuel the truck has used is among the cleanest there is. A new fuel filter was installed this afternoon. The old filter was examined carefully and there were no readily apparent imperfections discernable.
The Duramax will be driven for the weekend and then re-sampled early next week. We will post the results here for all to see..
George Morrison, STLE CLS

10-25-2002, 20:55

First of all I want to thank you for doing this testing. It looks like it's not something any of us could do properly.

Sounds like possibly the filter media itself is contaminating the fuel? Fibers? Where else could the particulate come from?

10-25-2002, 21:43

Dennis, (the filter mfr you referred to me) has some sample data that he fwd, but I have yet to talk with him...

10-26-2002, 17:10
george morrison

originaly posted under "fuel filter replacement"

[if this filter is installed improperly ("O" ring rollover, etc.)fuel, as with water, will always find the easiest way through a channel which translates into just what our analysis indicates:]

The "O" ring roll over confused me, are you refering to one of the two "O" rings on the out side of the fuel canister or that large internal ring in the center of the fuel canister.

If you could expand on this subject it would be much appreciated

george morrison
10-26-2002, 17:39
Regarding the "0" rings. The internal '0' ring specifically; however, the removed fuel filter '0' ring looked fine. All of the 0 rings were closely examined and did not reveal any cuts, roll-over or reason for by-pass.
Fuel filters are constructed by human beings (except for the CAT fuel/oil filters which are totally robotically manufactured and incredibly flawless) and can have an occasional mis-build and I mentioned previously, if there is a hole or poor glue, the fuel will find its way through.
We will just have to wait until the end of next week for another analysis result.
I forwarded the results to Jim/Diesel Page for posting..
Again, if anyone else cares to do a before and after fuel test, please contact me as I would be most happy to provide the fuel analysis kits for another test project before/after sample.
George Morrison, STLE CLS

10-26-2002, 18:27

If in fact you find out there is dirty fuel reaching the injectors, what can be done about it? Is there a real world fix?

Greg, suggest adding a Racor 2 micron filter unit along side your frame between the tank and OEM filter.

John, is working on a filter fix of his own.

Baldwin makes a OEM replacement filter that is suppose to filter quite well. I am waiting on there feedback on the micron rating and efficiency.

Is there a solution now? My injectors are wearing away as we speak!!

Thanks for doing the test too!!

george morrison
10-26-2002, 21:22
Regarding a 'real world'fix. One of the fellows on the 6.5 site portion ran a 'before and after' on a Racor "S" series and it was indeed a 2 micron 98% efficient filter, very similar in performance to the new CAT high performance 2 micron absolute filters. Our OEM Duramax is 'supposedly' the same filter medium, same performance level. This is what does NOT make sense with our first test..
If the OEM filter does not meet the 2 micron absolute performance level, we will source one that will!
It is absolutely imperative that we have a filter capable of 2 micron 98% efficiency as we need to minimze the 5 to 10 micron component. This is the particle size that creates high wear in our pump and injectors.
The fuel analysis that we are doing actually counts and calculates the number of particles per gallon for each size range from 2 microns to 5 microns to 15 microns, very accurately.
Plus it computes the amount of water being carried in the fuel in parts per million, so one knows exactly how much water is present, not a vague percentage.
We will now have to wait until Thursday or Friday for the second run fuel analysis reseult to be complete.
George Morrison, STLE CLS

10-27-2002, 05:25

I wrote to Baldwin Tech support asking for nominal and absolute Beta specs on their BF7727 fuel filter for the Duramax and they quoted "2 micron nominal". Nominal is the Beta=2, 50% efficiency (filters 50% of 2-micron particles). They did not quote an absolute spec. So, if the RACOR is really 2 micron absolute, it would be better … at least on paper.

10-27-2002, 07:56
-thank you george for your efforts, will be watching for more information on this

10-27-2002, 08:34
Keep in mind that the lack of a lift pump will require a free flowing filter. A super fine filter as proposed can/will restrict flow and fill up quickly UNLESS it is adequately sized. The solution wil not be petite or pretty, but WILL be effective and low maintenance.

george morrison
10-27-2002, 09:43
The ultra fine fuel filter restriction aspect is most interesting in that many times one can change from a 20 micron 50% efficiency to a 3 micron absolute rating and yet achieve a reduction in restriction AND greatly increased filter capacity enabling the ultra fine filter to actually last longer than the coarse filter. It sounds impossible but with the introduction of the new synthetic or micro-glass filters, filter efficiencies have been greatly increased.
Old tecnology paper/cellulose filters, due to the methodology of making paper, is a very inexact science. When a 'tight' filter was needed, say a 10 micron absolute, due to the manufacturing imperfrection of paper, sometimes as much as half a filter surface would be completely closed to enable a 10 micron rating! With the new 'manufactured' elements, the syntheteic or glass medium is made with 10 micron spacing throughout the medium, enabling 100% of the filter to flow oil.
I have replaced many 20 micron cellulose Beta 75 (50% efficient) filters with 3 micron synthetic media beta 200 (98% efficient) in hydraulic systems and had the filter life double over the cellulose.
The same is true with the Mobil Delvac synthetic media oil filters. They will easily go 50,000 to 75,000 miles between changes on the same over the road trucks that previously were changed at 10,000 to 20,000 miles. Yet the Delvac filter is a 10 micron beta 200 vs. the 30 micron beta 75 for the paper oil filter element.
We saw the same thing on our current VW TDI program to replace the paper fuel element (which is a 2 micron 50% efficient) with a CAT 2 micron 98% efficient. The OEM VW paper fuel filter drew over 8 inches vacuum requirement, while the CAT element was 2 inches vacuum.
Thus we have the possibility of replacing an OEM paper element with a synthetic or micro-glass element that will filter better, have less restriction and last longer!
George Morrison, STLE CLS

10-27-2002, 13:18
I will try and get some suction test results with the 2 Micron filter this week.

10-27-2002, 13:55
Does Racor make a OEM replacement filter that has the qualities we need.

I buy my filters from John and they are Racor brand called Interceptor. What are ratings on this filter?

Ya'll have me scared to death about my injectors. I plan to keep this truck for ten years.

Thanks for all the info guys!!

10-27-2002, 17:18
George: Thank you for the effort you are putting into this extremely important topic. I will be owning this truck for well over 15 years. 5 to 10 yr.. from now I do not want nor can I afford visits to the dealer for injectors, a pump, or anything that is going to get into the thousands to repair. I am very interested in the work you are doing for us. I don't speak up very often here, but believe me I read everything in this thread. I am sure their are many others like myself that really appreciate this. I just wanted to say thanks from all of us silent members out here.

I also thought about what JK brought up, but never thought about the results you get with a high quality low micron filter like Caterpillar, actually lasting longer.

Once again, thanks big time,

10-27-2002, 18:28
I have the Racor 2 micron on my 6.5TD and it is doing a great job. Not sur ejust how much restriction is there but I plan to find out this week. From other tests i have seen on other sights the restriction is actually less as George stated. Winter time might be a problem but the Racor is available with a heater and thats what I have.

10-27-2002, 18:53
If you get a filter that will mount to the frame and not stick below the frame it will have at least a 60gph rating. What would be the very most the Duramax under full load full throttle would draw? I can't think that it would be more than 10 or 12gph would it? If so you would be using a 60gph filter and it only has a pressure drop of .05 psi at full load, now that is not much restriction and if you are only using 20% of its capacity then restriction is almost nothing. Even if you had to install a lift pump it would be better than a few thousand dollars for new injectors. SOme of you need to do the fuel analysis and see just what you are buying, I think you will be disappointed. My fuel here is good quality fuel but its really dirty stuff. I plan to pull the injectors out of my TDI and 6.5 to see what shape they are in. Both only have 50K miles on them but I have been burning this dirty fuel for over half that time. George can tell you stories of injectors that only lasted 12-14K miles under those type of conditions. Of coourse this was on high pressure systems like the Duramax.


george morrison
10-27-2002, 19:16
In talking with a Racor engineer last week, our Bosch pump is consertavitely rated 60 inches! Our current OEM filter draws less than 8 inches, so an additional filter is no problem; in fact GM is currently working on a primary to put in between the present filter and the tank. What do you think that is telling us
It can therefore easily handle a both a primary and secondary fuel filter, especially if one or both are synthetic or microglass media. Moreover, if it is 'clean' fuel that the pump is processing, THAT is the key to both pump and injector life. i.e. if the pump has twice the load, if the fuel is ultra-clean, the increased load is much better than processing dirty fuel at half the load..
George Morrison, STLE CLS

10-27-2002, 19:28
Okay boys

I'm on board here.
Who's going to build a kit to add a additional higher quality filter to the Duramax trucks. I'm buying as soon as it's announced.

Greg/JK who's build it??

george morrison
10-27-2002, 19:45
How I wish we could post photos on this site! I have some incredible scanning electron micriscope photos of failed injectors at 95,000 miles; totally, completely destroyed. Due to dirt. Current diesel fuel regulations are for 1980 3,000 psi diesel fuel systems in which injector replacements were $28 each. Our current 30,000 psi fuel systems require ultra clean fuel to live. To meet current federal #2 diesel fuel standards, diesel fuel is only filtered to 30 microns when it leaves the refinery. The 7 micron particle is the Duramax fuel system killer. This is why CAT switched from a 20 micron nominal to a 2 micron absolute fuel filter for its Hueiu engines 2 years ago. Their fuel pumps and injectors were not lasting through warranty and the replacement costs were costing CAT millions of dollars until CAT switched to the new ultra fine filtration medium.
George Morrison, STLE CLS

Tim B
10-27-2002, 20:07
Well now I'm curious. Does anyone know how good the filters are on the Dodge and Ford diesels ? Do they have the same potential problems that we do ?

Tim B.

george morrison
10-27-2002, 20:15
Regarding Dodge & Ford. That is a very good question.. They have the same high injector pressures, thus the same need for ultra-clean fuel and fuel filters capable of doing same. I have not visited those sites lately but would very like to develop data for those installations.
I am fairly certain that they probably do not have adequate fuel filtration. Every time I have visited the sites I see numerous posts regarding injector change-outs, problems..

10-27-2002, 22:51

Who presently makes such a filter that we can use or install? I got 21000 miles on my truck and I want to hurry up and do something.

Do you think this filter GM is coming up with will be a TSB?

10-28-2002, 04:56
The Racor unit works great and replacement filters are reasonable. I use the 2 micron on my 6.5TD and it removed 94.6% of the 2 micron and larger particles and 96.4% of the 5 micron and larger particles. Plus these have a built-in heater as well. Give me a call.

10-28-2002, 07:02
Another good filter/separator is the Baldwin DAHL 100 (also marketed by AMSOIL). It's rated at 60 GPH and .76 inHg flow resistance. It also comes with an optional heater and uses inexpensive 2-micron replaceable elements. (http://www.baldwinfilter.com/products/dahl.html)
I bought it for my 6.5 (about $100 from Westfleet.com) but never got around to installing it so I'll be installing it on my new D/A. Looks like it will mount on the frame rail in front of the fuel cooler but I haven't decided how to best tap into the fuel line. Per George's comment that the Bosch pump can draw 60 inHg I think a need some pretty good hose and fittings. Anyone have any suggestions?

10-28-2002, 08:24
Hey everybody,
Anybody know anything about the Luberfiner LFF3786 which is listed as a replacement filter for our trucks. It is 39.99 at Autozone marketed under the Deutsch name? I know Luberfiner is owned by Champion Labs. Might be worth checking into.

[ 10-28-2002: Message edited by: Nut4Trucks ]</p>

10-28-2002, 09:32
To answer a quick question here as to the origin of the factory element:

I believe that there is ONE mfr making this element/housing, and all others are relabeled. I may be wrong here, but I doubt it...

10-28-2002, 14:05
Got off the phone with Technical Support at Racor and he tells me that the OEM filter we have is a 2 micron fliter at 99% efficiency. If that is true, then why are we having problems associated with dirty fuel?

He also told me he has heard that GM and Ford are coming out with a second add on filter like what we here are talking about.

I am waiting on George with his test but I am thinking of purchasing the Racor R460 with a R60S filter. I will have to make a bracket to bolt to the inside of the frame right in front ot the cooler.

Any thoughts?

10-28-2002, 14:17
Couple more thoughts:

1)It is VERY unlikely that the factory filter does as well as claimed.

2) Adding a better filter is a great idea, BUT the fine filter should be AFTER a primary filter.

I'm not rushing into this one...

10-28-2002, 14:51
Here's one more idea I got from a local Injection Service. One of the techs there suggest that the main problem is not dirty fuel but the lack of lubrication due to the reduction in Sulfur in Diesel fuel. He says add a fuel additive such as Stanadyne.

He also suggest that most injections systems can digest particles up to 10 microns with no problem.

10-28-2002, 16:11
When I had my 8 injectors replaced the Diesel tech said the same thing about sulfur content and lack of lubrication. However the shop manager opened a GM technical case and GM recommends against the use of fuel additives.

10-28-2002, 16:25
One thing to remember is 5-10 micron particles at 30,000psi will be like a sand blaster. Dirt does more harm to injectors than lack of sulfur. I beleive in fuel additives but it is not a cure for everything aspecially dirt. If we had picture posting ablities I could show you my fuel analysis report and it was DIRTY stuff.

george morrison
10-28-2002, 16:35
The information I am sharing with respect to injector and pump wear is the result of a many hundred thousand dollar study funded by CAT relating to injector life, or lack thereof. In this very thorough injector wear study, it was determined that the 5 to 10 micron particle size content bears a direct relatonship to wear rates. The reduction in sulphur content had minimal measurable relationship to wear rates when compared with dirt/particle counts.
This is a rather long story but the short of it is that our fuel systems are basically hydraulic systems. 20 some odd years ago hydraulic system manufacturers found that fine particle contamination is what was destroying/reducing pump and servo valve life. They established a system of 'cleanliness codes'. For our fuel system pressure and componentry, we should be achieving a minimum of a 15/13/10 ISO cleanliness. For a garbage truck hydraulic system to live, it needs a minimum 18/16/14. The higher the number the more allowable particles in the size range of 2, 5 and 15 microns. Most diesel fuels from the pump are in the region of a 20/18/16 or even as high as 24/22/19... Not even fit for a 1,000 psi hydraulic system in a garbage truck much less a 30,000 psi fuel system!
Thus, if we have a fuel filter which is only 50% efficient in removing the 5 to 10 micron particle size, fuel injector and pump life is going to be short. The fuel system/injectors will no doubt make it through the warranty period but take a look at the posts on this site and the 6.5TD and you will notice a trend.
Dirty fuel was almost acceptable with the old mechanical, 3,000 psi injectors but with our high pressure, high precision injection, contaminants mean drastically shortened life.
In the next weeks we will know exactly how efficient our fuel filter is on the Duramax.
George Morrison, STLE CLS

10-28-2002, 16:53
I've been running Wix fuel filters from NAPA. I emailed Wix asking for nominal and absolute Beta specs on their 33810 part # filter for the Duramax. Here is the reply I received from them:

OE does not specify a nominal rating. The absolute is 2 micron and our 33810 part number meets this requirement.

Thank you for your inquiry

Chris Greeson
Senior Technical Services Manager

[ 10-28-2002: Message edited by: Micheal Tomac ]</p>

10-28-2002, 17:40
Ok George I am convinced the fine particles are our enemy. I am going to purchase a second filter for my truck. John suggest putting the fine filter after the OEM filter. I can't see where it would make a difference on the quality of fuel reaching the pump and injectors. I just see one or the other will need replacing sooner than the other. Any comments on where the additional filter needs to placed?

George I don't know what you do for a living but you sound like you know what your talking about.

This site is full of good resources!!!

george morrison
10-28-2002, 17:59
Regarding additional filtration. I want to see exactly what our OEM filter is doing efficiency-wise. We have had several additional volunteers who are going to be doing 'before & after' tests on their pump source fuel and the after the filter qualities. Then we will know exactly what we are dealing with particulate-wise and can then make decisions based on this information. I would suggest waiting a few weeks until we get the data completed..
We will share all of the results with everyone here as the fuel analysis are completed.
George Morrison, STLE CLS

10-28-2002, 19:08
Last sentence in my previous post.

10-28-2002, 19:26
I might install some better filters inbetween my aux tank and the oem tank..and just fill the aux tank and transfer all the time..

I will wait for your results, of course..

Thanks for the Cat research..I have alot of friends who work at the Decatur Il Cat Plant.. smile.gif

10-28-2002, 21:00
I guess a few more weeks won't kill me or my truck.

Thanks again George!!!

10-29-2002, 23:43
Hey George,

I got my second kit today and pulled the sample post filter or just before the cooler to be more exact. Used my new remote start to control the flow. I was actually surprised that the flow was as slow as it was. It really didn't shoot out at all. For the sample, I let the line hang down over a pan and just caught samples out of the stream. I filled, shook and dumped 3 times and kept the 4th sample. I will sent them UPS tomorrow.

10-30-2002, 08:45
I've got the test gauge that is used to measure vaccuum after the filter. My plan it to use this hose, along with an air hose/rag to create a slight pressure in the tank and push the fuel through the filter this way...

10-31-2002, 09:31
What is the best filter on the market for the Duramax?

10-31-2002, 10:04
The best filter or filters is still to be determined.

To answer the question on why put a fine filter after the OEM filter, think about it like this. A filter is a bucket with a screen on the bottom. It has a limit to how much it can hold and it holds only the particles that are larger than the holes in the screen. If you put sand through the bucket with a large screen, you catch the big stuff. If you run it throught a med screen you catch the med and big stuff. If you run it through a fine screen, you catch all sizes. Now, if you put them in series or one after the other, and put the fine screen first, what good with the others do? You will just have to empty the fine screen bucket more often. Now, if you use the big followed by the med and finally the small, each bucket will catch different sizes and you will spread out the amount of debris between the filters and they will last longer because they won't fill up as fast. Each bucket can only hold so much. Staged filtering is a common practice in industry.

The whole question here is what size screen is on our bucket? Over simplified I know, but it illustrates the point. JK is right, rushing in could make it worse. The right media in the right size filter in the right location is what is needed and only careful planning and testing will get us there.

george morrison
10-31-2002, 15:31
We have Tom's re-run from his post filter tomorrow am, Friday. John Kennedy's should be completed by Monday.
By Mid-week we will have 3 complete sets of before the fuel filter and after the fuel filter analysis results which will a good sampling of data on the efficiency of our OEM Duramax fuel filter..
George Morrison, STLE CLS

george morrison
10-31-2002, 17:27
Tom's fuel before and after fuel analysis results are complete. Tom sampled his local Galisto, NM source and the capsule results are:
Cetane Index: 47.31 (very good!)
Water 45 ppm (good)
ISO Cleanliness: 18/16/12 (Target 15/13/10)
Particles per gallon equivalent:
&gt;2 Microns: 8,353,495 particles per gallon
&gt;5 Microns: 1,873,575 particles per gallon
&gt;15 Microns: 147,615 particles per gallon

&gt;2 Microns: 1,211,200 particles
&gt;5 Microns: 302,800 particles
&gt;15 Microns: 37,850 particles

The AFTER filtration analysis reflected the following.
Water: 51 ppm (HIGHER than pump of 45 ppm!)
ISO Cleanliness: 16/15/12 (Target: 15/13/10)
Particles per gallon:
&gt;2 Microns: 1,585,915 particles per gallon
&gt;5 Microns: 651,020 particles per gallon
&gt;15 Microns: 136,260 particles per gallon

Filter efficiency:
&gt;2 Microns = 81% reduction
&gt;5 Microns = 65% reduction (most critical size)
&gt;15 Microns= 8% reduction

So for the most critical particle size our OEM filter is slightly more than 50% efficient and not near the 92% efficiency level for the CAT filter or the Racor "S" on Greg's 6.5TD.

Additional note: Tom's previous "after the filter" sample came back reflecting an ISO of 19/18/15, actually worse than his pump fuel sample. He either had a defective fuel filter, a mis-install, or rupture. The first test filter had a little over 8,000 miles on it. The second filter test was for a filter installed Friday and driven over the weekend with less than 200 miles on it.
More results next week.
George Morrison, STLE CLS

[ 10-31-2002: Message edited by: george morrison ]</p>

11-01-2002, 07:05
Very interesting. George, do you know what the margine of error is for these tests? I'm not referring to the possible human error involved in the sampling of the fuel, but the actual measurement of the particles?

From the few tests I've seen here it makes wonder about a few things. The first is there have been at least one area with both filter tests where the post-filtered fuel was worse than the pre-filtered fuel (IIRC previous test had worse particles, this one has worse water). I don't understand how a filter could be adding contaminates? Perhaps since this last filter is so new, it could have had water in the filter media from the manufacturering process and is slowly releasing it? Is it possible that there might also be some particle contaminates left from the initial manufacturing process?

Also, how is it that a filter can be more effective at filtering smaller particles and less good at filtering larger particles? I don't understand how if there are gaps big enough to let a larger particle flow through how it could then trap a smaller particle.

I'm going to go back and re-read how the samples are being captured. This is very interesting stuff.

george morrison
11-01-2002, 07:29
The margin of error for the particle counting is very small. The most probably cause for variations is sampling technique. The problem (only one to my knowledge) of the 'after filter' indicating higher particle counts than the before was for a fuel filter with 8,000 miles on it. The most likely cause of the higher particle count would be filter failure, defective filter, improper installation (not so difficult with the Duramax installation!),etc. as opposed to the ISO 9002 lab variation. In other words, from my professional experience, the particle counts, overall results is the one aspect we can count on; good sampling technique is sometimes very difficult to accomplish. That said, I have much confidence in the sampling techniques used in the high PC case so I am most suspect that it was a filter causing the reading.
Also, the sample point for the 'after filter' was the return line to the fuel tank. This then is after the fuel has made its complete trip through the filter, pump, injector circuit, and injectors. Thus, if we have a component producing wear particles, a failing component, carbon, etc. anywhere along the route, our particle count for this sample would reveal that debris also. This may be the source for the large particles and may well increase the particle counts.
We have additional 'before & after' samples that should be completed next week which are using a different sample point for the 'after', that being immediately after the filter, pump, but before the injector circuit. However, in this case the engine will not be running, eliminating the fuel system dynamics which can greatly affect fuel filter performance; i.e. the opening and closing of the injectors creates harmonics which back feed to the filter and can cause a cleansing action in the filter medium. In other words, a filter that may be labatory rated a 2 micron 98% efficient may test at 2 micron 65% efficient in real world operation on the engine.
This is a developing, on-going project and as more data comes available we will obviously be better able to make decisions..
George Morrison, STLE CLS

[ 11-01-2002: Message edited by: george morrison ]</p>

11-01-2002, 07:49
Thanks George, that info was very helpful!

11-01-2002, 12:58
George, thanks for the information. I have taken your posts and forwarded them to my GMC service manager and talked with him. He said that there weren't any current cases that had reached GM's review (legal, which is the step before a TSB is published)but indeed there may be analysis being done at the R&D level. He informed his two senior Techs of the concern and ongoing user testing and they will bring it up at the zone service conference being held here in the DFW area next week. This forum will help to start the TSB analysis process. Although he hadn't seen significant cases of injector failure on the D-max, he fully expects it to be a significant warranty issue with the Racor and current PSI. He agrees from past experience with the 6.5 that the current filter probably doesn't meet the needs of the D-max and awaits more analysis so that a supplemental filtering solution can be found. Any information that you could provide will be forwarded to GM for action. He also promised to forward me with any action within GM that he can find as it enters the service channels. This dealer is in the top 5 nationally for sales/service of GMC, so GM will listen. You can contact me offline if you would like, otherwise I will continue to monitor the analysis and update the dealer. By the way, I am not empoloyed by the dealer. Although new to GMC's and diesels, my affiliation with the dealer results from the various Pontiacs I have purchased there over the years. I am active in Pontiac clubs and we work together to put on local and national Pontiac shows. Gotta go, time to see if I can line up the 2004 GTO for a show after it's introduction at the LA/Chicago Auto shows in January.

Randy Allen

george morrison
11-01-2002, 13:40
Randy, if you would be so kind to e-mail me your e-address, I will forward the original fuel analysis results to you. The full reports are much more forceful in presentation in that they graphically compare results with target ISO, etc. My e-mail address is avlube@netwalk.com.
Gosh, it sounds like you have an incredible dealer working with you! Most of the dealer folks I talk with have absolutely no interest or understanding of what we are working on!
George Morrison, STLE CLS

[ 11-01-2002: Message edited by: george morrison ]</p>

11-01-2002, 14:57
Here is a e-mail I received from a Balwin Filter Engineer. I thought someone had said earlier that this was not the case on the filter, maybe it was Greg. I can't remember. Anybody have any speculations as to whether the following statement is true? This BF7727 is Baldwin's OEM replacement filter for the Duramax.

The BF7727 is 95% efficient at 2 micron. If you have further questions, please feel free to contact us.

Service Engineer

11-01-2002, 18:52
Baldwin says it is 2 micron, but their is only one true way to find out and thats put one on and do a sample analysis. So far the Racor and Cat filters are proven to be 95% at 2 micron.


George Gozelski
11-01-2002, 20:45
Does Racor make a replacement filter for the Dmax or do you have to add one on in addition?

george morrison
11-01-2002, 22:36
As Greg pointed out the Racor "S" series has proven to be an excellent filter; 95%+ effective for the 5 micron and greater size spectrum which is our target. The regular Racor's, however, are pretty much the same as OEM and are comprised of simple cellulose filtration. To achieve the level of filtration and capacity we need, the filter has to be constructed of a synthetic or microglass type media. The CAT and Racor "S" are synthetic or a synthetic blend type media. If only we could get CAT to expand its filter line we would have that filtration level.. But, CAT recognized the lack of quality fuel filtration and had to go out and build a factory to make filters capable of achieving the level of quality/filtration needed for maximum fuel system life.
George Morrison, STLE CLS

11-02-2002, 07:50
I e-mailed Racor about a possible filter solution and they are sending me free of charge a 645R filter head and a R45S filter. I think it is awsome that they are sending me one free but I don't like having to fill the filter and bowl with fuel when I change it. I most likely won't use it. Too bad they wouldn't send me a 400 series filter with a primer.

11-02-2002, 08:36
WELL, whaddya know! right under my nose the whole time in the Baldwin catalog!

Thing is I'd suspect it is just a remarked OE filter. Guess I'll have to order one and find out...

11-02-2002, 08:39

I e-mailed Baldwin back and ask what the filter media is made of. No reply yet. I just sent it this AM.

George Gozelski
11-02-2002, 12:20
This is great that we have people on this site trying to help other Dmax owners! I commend all of you for digging into this filter thing! I'm about due to replace my fuel filter, so I'll wait until all of the outstanding replies from the previously mentioned manufacturers have been returned! Does anybody know what currently is available from all of the suppliers out there. I think we need to list all of the available fuel filters and rate them when this all gets sifted out!

11-02-2002, 12:56

It appears there will be an additional filter added to our trucks. Racor makes the GM Filter and they sale a filter of there own. Baldwin makes one as well. I think the argument is that none of the OEM replacement filters do a good enough job.
We all are waiting on the final analysis and then George Morrison will source out a filter for our use. You can thank him.

11-03-2002, 10:45
Here is a link to a interesting article about clean fuel.


george morrison
11-03-2002, 11:25
That is an excellent article, one of the few written on the subject of the direct affect fine particle concentrations have on fuel system life and performance. I was surprised to see the author being an employee of Shell in that the major fuel companies are staying away from the fuel cleanliness issue like the veritable hot potato. All major refineries stop filtration at 30 microns. Anything below 30 microns gets a free pass. The 5 to 10 micron particle is our problem size particle. No one is filtering to this size. Likewise, no oil company is GOING to filter to 3 microns as a refineries efficiency, the refinery manager's bonus, is predicated on gallons throughput. Putting a 3 micron final filter would reduce throughput gallonage tremendously and cost the refiner gazillions.. So, we are not going to see any refiner step up, voluntarily, and start ultra fine filtration unless regulated to do so.
Thus my surprise with the Shell employee authoring the article.
So, the responsibility to ensure our injector/pump life rests on our shoulders.. The Duramax fuel system/injectors are going to live through warranty; however, if indeed we have a 65% efficient fuel filter, our fuel system is going to be on constant deterioration resulting in decreased power, increased polution, increased cost and eventual early failure.
Off my soapbox...
George Morrison, STLE CLS

[ 11-03-2002: Message edited by: george morrison ]</p>

George Gozelski
11-03-2002, 14:30
Does anyone know if a CAT fuel filter setup could get "morphed" into a Duramax application?

george morrison
11-03-2002, 16:11
Once we really know what we have OEM-wise we will then be able to pursue possibilities. I think more 'before & after' fuel analysis results are needed prior to proceeding with alternative fuel filters. We should have more fuel analysis results this week. It is nice to know that there are reasonably priced 98% efficient fuel filters available, however, if fuel analysis results continue to report that the OEM fuel filter is no more than 65% efficient.
George Morrison, STLE CLS

11-03-2002, 18:56
George is right, we need more data…. I also sent some questions to Baldwin and its interesting to compare the following with the reply Todd Eldridge received from the same Baldwin rep.

I emailed Baldwin about their fuel filter on 10/14/02. Here are their responses

"Thank you for contacting me again. The BF7727 is a 2-micron filter. Meaning that its nominal efficiency is at 2 micron. Thanks, (nominal implies 50% efficiency)

Service Engineer"

To which I replied,

“I'm skeptical about RACOR's claims (i.e. that their Duramax OEM fuel filter
is 2 micron absolute). I'm not an expert but it doesn't sound possible
for a filter that size to be rated at 2 micron absolute. Can you comment on

This is their second reply,

“Your are correct. SAE test procedures cannot test to two micron absolute. The BF7727 is two micron nominal.

Service Engineer”

george morrison
11-03-2002, 19:06
The fellows over at the TDI site did 'before and after' fuel filter tests for both the CAT and the Baldwin equivalent of the CAT filter and both were 2 micron 98% efficient or Beta 200 in the filter vernacular or what was referred to as 'absolute'. (nominal and absolute are not real terms in today's filter technology: filters are classifed by their multi-pass performance and then a ratio is calculated predicated on the 'before & after' throughput.) Since our filter only gets one throughput, that procedure does not directly apply. However, our real world tests do! As with the CAT TDI tests, if we get a filter removing 98% of the 5 to 10 micron single pass, we will have a solution to the dirty fuel problem...
George Morrison, STLE CLS

11-03-2002, 19:40

I put a lot of miles on my DuraMax weekly. If I can help with your mileage test... let me know.


11-04-2002, 08:38
Made contact with a Stanadyne Dealer in New Orleans and he told me that no body made a completely synthetic filter. He said that Racor's "S" is a synthetic blend. He sold Racor and Stanadyne. Liked both. As far as the cost is concerned you can buy a Stanadyne Filter head, element, primer and glass bowl for abouot $90 Replacement filters are $14.36. If you don't want the primer or filter bowl then the whole thing cost about $42. The element is a 2 micron filter and it is a 99% efficiency. Sounds too good to be true!! He also suggested staying away from Baldwin, Wix and NAPA brands.

george morrison
11-04-2002, 09:13
You found a pretty knowledgeable source for fuel filters and he is correct, at this time, the ultra-fine filters are indeed a blend of synthetic/microglass and cellulose. The synthetic medium requires some sort of form or stiffener as it is very soft and pliable. In pure synthetic filters a wire mesh is used to provide the support. At this point all ultra-fine fuel filters, including CAT, are a blend with the paper/cellulose providing the shape/form for the synthetic medium.
If you were to open a Delvac/Mobil1/AC Delco Duraguard Gold, etc. you would see a very intricate wire mesh structure supporting the synthetic medium.
George Morrison, STLE CLS

Brent - DIS
11-04-2002, 12:25
There seems to be some confusion here. I have Bill Howard from Racor on the phone as I type this. Background --- I am with DIS, and we have been a Racor dealer 20+ years.

S has nothing to do with "synthetic"

Racor uses the following formula:

S = 2 micorn
T = 10 micron
P = 30 micron

This only comes into play when you purchase an "add - on" unit like the 400 or 600 series complete element.

The FACTORY unit is a 2 MICRON filter. Recommended replacement 12-15 thousand.

Racor will not even disclose the material used (it is not just a simple cellulose filter as described above). They can not disclose all of the material used since it is propriatery to Racor.

NOTE: I reply to this because we have calls for a synthetic "new" filter that does not exist.

Bill did mention that they are sending a unit to Todd as a test to make something similar to what they have made for the Ford Powerstroke.

http://www.dieselpage.com/rac99upao.htm (for example)

[ 11-04-2002: Message edited by: Brent - DIS ]</p>

Brent - DIS
11-04-2002, 12:50
Efficiency rating of the Racor OEM filter used on the Duarmax.

99% efficient @ 4 micron

11-04-2002, 12:52
I just called Travis Winberg at Baldwin for clarification on their BF7727 specs.

Travis said he called their OE

11-05-2002, 19:37
This post is driving me NUTS!!!!!!!!!!

I bought 5 filters from DIS IN F4598

Could Brent-DIS please tell me if the above product is equal to or better than OEM filter, I sure hope its not worse,

Topic is excellent some of the terms dont mean a thing to me.

11-05-2002, 19:45

The IN 4598 is the same filter as the OEM. Racor makes both. The suspected problem is that neither do a very good job. It appears we will have some kind of addtional filter to our system. George Morrison is doing the test and will inform us all soon.

11-05-2002, 19:55
I think it's safe to say - as JK first pointed out - that there is only ONE Filter and it's made by RACOR - the OEM. The other manufactures are just buying from RACOR. Travis at Baldwin told me their filter is made by RACOR and we know that the GM filter is made by RACOR. So, the only question that remains is ... how good the ONE RACOR filter really is. And, it seems that George is well on the way to measuring the true performance.

11-05-2002, 20:16
The way it looks, the OE filter will NOT live up to any of the claims of 90%+ efficiency. George has the details, but it looks like mid 60% figures will be the norm.

Now the question is, are we going to cut lines and install the better filter in the technically incorrect primary position? It isn't going to be something I will be rushing into, but I'm thinking that I will NOT cut into the OE lines plus I can get the better filtration in after the OE unit.

george morrison
11-05-2002, 21:03
So far our test results show the OEM fuel filter to be 60 to 64% efficient in the critical 5 to 10 micron partical size. Even lower in the other size spectrums.. We have several more tests still in process but I would not anticipate any changes. I will post those results as soon as they become available. Additionally, in all our 'before & after' tests to date, there has been absolutely *no* decrease in water content in the fuels journey through the fuel filter/water seperator. None.. Water content has varied from 30 ppm up to 70 ppm. Whatever water level went into the filter came out the other side.
Stay tuned...
George Morrison, STLE CLS

11-05-2002, 21:54

I looked pretty good at putting another filter after the OE. No much room to work with. How do you think you can accomplish this feat?

11-05-2002, 21:57
How can you check for damage already done to the injectors?

11-05-2002, 23:16

I found where Fleetguard makes a line of fuel filters with a 100% synthetic filter media called Stratapore. They even have a remote mounted unit called Optiguard FH23000. It has a very easy to change element and no need to reprime looks pretty good. Haven't found a dealer yet!!!

11-05-2002, 23:44
What about the by-pass system? Will that not "grab" the 2 micron size?


11-06-2002, 04:10
I am very interested in how we can prove this is a problem to the dealer. I have 60,000 miles on my truck and I feel I have injector problems (blue smoke from the tail pipe at times and the smell of unburned fuel), but the dealer believes the problem has occured from the 4" exhaust and a POSSIBLE power box (but they can't show me where the power box is), so they will not investigate further. I am printing all of this post to use as ammunition for my case. I just want to get this fixed before my warranty runs out. I have already spent $200 for them to tell me I have nothing wrong, because of no codes and of course the so called box and exhaust. :mad:


11-06-2002, 06:28
A bypass doesn't apply to a fuel filter system since the fuel only takes a single pass through the filter before being consumed. A bypass works for oil because the oil is constantly being re-circulated through the filter(s).

John K,
If it turns out that there is not a practical way to add a better filter after the OEM primary filter, would it be acceptable (though not ideal) to put a "better" filter in front of the OEM filter?

[ 11-06-2002: Message edited by: jbplock ]</p>

11-06-2002, 06:59
George, JK

Is the efficiency rating of ~60% for the samples that were taken directly after the filter? From a previous post here George had said the following:

"Also, the sample point for the 'after filter' was the return line to the fuel tank. This then is after the fuel has made its complete trip through the filter, pump, injector circuit, and injectors. Thus, if we have a component producing wear particles, a failing component, carbon, etc. anywhere along the route, our particle count for this sample would reveal that debris also. This may be the source for the large particles and may well increase the particle counts.
We have additional 'before & after' samples that should be completed next week which are using a different sample point for the 'after', that being immediately after the filter, pump, but before the injector circuit. "

Have the results from the tests where the sample is taken directly after the filter come back yet? If the 60% efficiency rating is for fuel that's getting recirculated back to the tank, why is that so bad? If the efficiency for the fuel actually getting to the injectors is much higher (&gt; 94%) then it should still be quite good, no?

george morrison
11-06-2002, 08:46
Yes, the results for "after filter only" are complete and the results are consistent with our previous results, at 62% efficiency for greater than 5 micron particle size. The 2 to 5 micron size spectrum was only 44% efficient... More results this week but I think we have our answer at 60% to 64% efficient in the 5 micron component, the size most affecting our fuel system life.
George Morrison, STLE CLS

11-06-2002, 09:53
Comment on water separation

I changed my first filter at 12000 miles when I opened the filter drain cock for the first time only 2 drops of water came out (I assumed no water in the fuel I have been buying).

I cut the fuel canister in two and observed that only the bottom 1/2 was a discolored black and the top half was a discolored white, not what I had expected.

So I have to ask this question????? has my fuel filter been on BYPASS the whole time, but I just read there isnt a bypass so why is the filter so clean and no water?????????

Any response would be welcomed.

[ 11-06-2002: Message edited by: letsgo ]

[ 11-06-2002: Message edited by: letsgo ]</p>

11-06-2002, 13:21

I add my thanks for all the work you are doing on this issue. If you need additional samples let me know and I'll forward one from my truck too.


11-06-2002, 13:29
What you saw is completely normal, as I have observed it in every fuel filter life test that I ever conducted. The fuel flow almost always starts at the bottom of the filter(depends on design) and works its way up as the media gets contaminated. The white was just the unused portion of the filter. If you noticed when you changed the filter there was a tube that went quite a ways into the center of the filter, its near the bottom of the media when installed and causes the suction pressure to be centered around there at the beginning of life. Had you ran the filter longer the media would have been used and coated entirely as you expected to find. Mine was around 3/4 used when I changed at 13k.

11-06-2002, 14:00

Any ideas on what kind of filter set-up might fix our problem? The Stanadyne FM-100 is looking very promising to me.

11-06-2002, 14:06
I've got to add something else here before the lynch mob lights the torches and shows up on Racor's door.
The 95% efficiency numbers are obtained using fuel conforming to ISO/TR 13353, the ISO test for fuel filter particle retention and efficiency. This fuel is dosed with a much larger percentage of contaminant than you will ever see out of the pump, it looks black when totally mixed. This is done first to speed up the test so it doesn't take a month to perform, second it levels the playing field so everyones results can be compared at a predetermined contaminant level(George I assume will agree that initial contaminant level in fuels will vary widely depending on location), and third sets the contaminant at a level we should never see(makes the test harsher on filter).
With that said, as contaminant levels drop, your effective efficiency at removing them will fall accordingly.

11-06-2002, 14:08
Did you find a spec on the Stanadyne FM-100's flow resistance (in inHg)? They quote a flow rate of 80 GPH but I didn't see a spec for flow resistance on their web site. Sent them an email request a few days ago but haven't heard back yet. It does look like a nice filter ( if the specs are as good as they claim).

11-06-2002, 14:19

No I don't, but as George stated earlier tha our pump has a 60hg and the oem filter takes 8 of that. Therefore it will handle one more filter. Besides if it doesn't and it will, stanadyne makes one with a lift pump on it.

11-06-2002, 14:29
Tech support at Stanadyne told it would be 2 inhg and 1psi on a new filter. Looking better all the time. The whole unit only cost $90 and that is with the head, element, hand primer and plastic bowl.

11-06-2002, 14:32
Thanks Todd.. Yes remember reading George's post on our pumps 60inHg rating and you're right that it should easily handle the load from the added filter. It just would be nice to know the Stanadyne spec. I just read one of the data sheets on the Standyne website and it states that the flow resistance spec is available upon request. If I get a response I'll post it. Being a chronic worrier, I 'm concerned that if I ever had a pump problem the dealer could claim that it was due to the added load of the extra filter... just be nice to have some back-up data in that case.

[ 11-06-2002: Message edited by: jbplock ]</p>

11-06-2002, 14:45

Read my last post. I was posting the same time you were.

More Power
11-06-2002, 16:03
We have to assume that Bosch, Dmax, and GM designed these fuel systems to operate in the real world. Certainly, the cleaner the fuel the better, but there comes a point at which "good enough" is really good enough.

What I can't seem to locate in this thread is any data that equates a certain fuel cleanliness level to a certain number of miles or hours of operation, with comparisons between different levels of fuel quality.

What most people want to know is, what is the typical fuel system life with OEM filters, and what would it be with better filtration? Good data and proven results - in the real world...


11-06-2002, 16:18

What I see is that there is proof that dirty fuel causes all kinds of problems in the new modern day high pressure injection systems. You can look around on the internet and see that. George quoted CAT's study of just that. I think if we wait till we have our own proof of this it will too late. I personnally don't have $5K or $6K laying around to buy injectors and/or a pump, when I can buy a $90 filter that will most likely eliminate the problem. As you can see adding another filter won't hurt. I went by my dealership today and ask the service manager if he would void my warrenty if I added another filter and he said most definately not. I have a great Service Manager, he's been a friend for at least 20 years.

11-06-2002, 17:40
I'm taking a middle ground here. The power of the internet is a great resource, BUT those poor filter guys must be really "dissing" it for all the calls/tech inquiries that they are getting from all of the people going off in ten different directions. :rolleyes:

As to data and proof, I am a simple man. I feel I am a pretty good judge of what works and what doesn't AND I know who to believe and not. Simply put if the post filter fuel is dirty enough (according to George) to harm hydraulic systems of a LESSER psi, with a better lubricating fluid, then it is obvious to me that this level of contamination is not good for our fuel systems. No need to beat me over the head get me to acknowledge this.

Sure GM and Bosch looked at what was required for filtration, spec'd it etc, but what happened when the bean counters said the price was too much? Did engineering have their sights set on 500,000 miles or 100,000.1 miles? These guys ARE in the parts business too!

It is obvious to me that we will benefit from improved filtration, but again, I'm not rushing into this...

11-06-2002, 18:52

I respect your knowledge on all these subjects and I am not sure why you not "rushing into it".

If the answer to cleaner fuel is adding another filter , then why not go ahead and add one. Post OE or pre-OE? The fuel still gets filtered. Only thing is you might have to change one of the filters more often than the other one.

11-06-2002, 21:41
Hi everyone new to the Forum. I have been lurking for a long time but decided this was a good topic to start adding my $0.02.

Just a thought but if the Fuel/Water Seperator is not removing the water from the fuel then why not unhook the sensor go have an adapter machined to fit in place of the stock filter and have the other side made to match a CAT Spin on Filter or the Filter of your choice.

There is plenty of room for a larger diamter and longer filter. More filtering area. Not to mention the fact that if the filter was a little longer it would be much easier to get a strap wrench on the filter.

Any opinions good or bad are welcome.


11-06-2002, 22:02
Choreboy I agree,
I just don't know how to do that.

11-07-2002, 06:45
More Power I have to agree with you to a point about GM and Duramax doing their home work on filtration. But even as much as I love my GM vehilces I know that things always have room for improvment and what comes with them is not always the best solution. They are just wanting to get throught the warranty period so they gamble on what it will take to do that and hope for the best.

I worked at Navistar for over 10 years and I can tell you that what they know does not always get applied. I can see this even now with a large account that I have thats building generator sets. What is needed to do the job right is far from what they want to do because as JK mentioned it all comes down to the dollar.

I have had the Racor 2 micron on the 6.5TD for awhile now and it always gets fueled up at the same station. We have a known quality of fuel and we know what the filter did new. I will be doing another after filter sample soon. This might shed some light on how long the R45S element will last.

We were looking at a Dmax a couple of days ago to see just where to put the extra filter. There is plenty of room just ahead of the fuel cooler. We are going to try and come upp with a bracket that will clamp onto the frame so holes do not need to be drilled. Their is plenty of room to put on the 660 or 690.

11-07-2002, 08:34
I agree with Greg and it is a great location. There is already two holes in the frame you can mount a self made bracket to. Just pick your filter brand as I am most likely going with Stanadyne FM-100. Cost and predicted performance.

11-07-2002, 09:56
Where did you see the holes? What I am in the process of is a bracket that will hook over the frame and then clamp to the frame. Making it out of 10ga so it will be strong. This way it will be a very simple no hole drilling deal.

11-07-2002, 10:22

Welcome to the forum! Talk about picking a ho-hum topic to introduce yourself! J/K :D Congrats on the truck and let us know if you get pics posted up for us to see.

IRT your idea for the add-on filter with the adapter, I don't think it's gonna work. The OEM fuel filter IS the water separator, not a separate unit. The water is supposed to collect in the bottom, set off the sensor if it reaches a certain level (which no one has ever seen this WIF alarm go off) and has the drain plug at the bottom. All of this is in the base of the filter. If you add another filter to the bottom of that one, the fuel will take the path of least resistance, probably the stock filter media. The only way to improve it is to add another filter in line.


So far, lots of great info! As most of you know, based on other peoples' research, I think that air bubbles and entrained air in the fuel is also a concern both from a performance and pump/injector life standpoint.

I gotta agree with JK and others, the engineers probably would like to do the ultimate setup, but the bean counters control the bottom line and we get the result of that. I wouldn't have spent $4,000 on upgrades if they did it the way I wanted it the first time around. ;)

To me, the ultimate fuel system upgrade would consist of the following:

1. Drop the tank and clean it of debris; investigate/upgrade the fuel pickup and screen to ensure there are no leaks and it won't get clogged far from home.

2. Disconnect the first fitting at the outlet of the tank and install a hose with hose clamp leading to the first, "coarse" filter mounted by the fuel tank.

3. Install another clamped hose to feed the prefiltered fuel to a pusher pump capable of handling diesel fuel for 100,000mi and supplying 5-10psi at 10gph. The outlet of this pump would have the quick connect male fitting, to which the factory fuel line (originally connected to the tank outlet)would attach. This would pressurize the line from that point on and provide the correct conditions for the factory fittings.

4. Replace the factory fuel filter with something with more fitration effectiveness and flow rate, as discovered by actual test results. I'd expect to replace the coarse filter every 15-20,000mi and the fine filter every 20-30,000mi unless a bad batch of fuel had a lot of contaminants in it.

This would provide the following benefits:

1. Elimination of air bubbles from leaks in the fuel system and entrained air coming out of suspension from too much suction/restriction on a partially clogged fuel fitler. I'm *theorizing* that this would give better, more consistent performance and fuel mileage as well as marginally longer pump/injector life. For more info on the effects of air bubbles and entrained air on a slightly lower pressure HEUI fuel system, check out www.texastowncar.com. They had injectors failing within 10,000-20,000mi of simulated use!

2. 2 stages of filtration to give longer change intervals and more effective fitration. This would hopefully give longer pump and injector life. This I'm sure drastically affects pump and injector life. As expensive as these pumps and injectors are, I don't want to pay for any until well past 200,000mi.

3. An electric pusher pump can reprime the system after a filter change and keep it primed, even in sudden weather changes that I beleive are causing the sudden rash of trucks dying or running weird.

4. This would help eliminate the dreaded "limp mode when the fuel filter clogs". I think this is very unsafe, especially when towing up a hill. To suddenly lose 80% power and have the TC unlock with no prior warning when you need it most is unacceptable.

Here's some more info from the only person I'm aware of to go more than 483,000mi on a Dmax without replacing injectors or a pump, BROKERS.

Quote: "We use a Racor 2 Micron fuel filter after the factory fuel filter,on all our trucks.
We buy fuel like all haulers,when ever we need it.
We have a 100gal bed tanks on all our trucks and it has a Racor fuel fiter and water seperator on it also.We always fuel the big tank since it handles the large nozles at truck stops.The aux-tank feeds the stock tank.
There is no black magic,just keep it clean !"


What filter would be best for the coarse filter?

What filter would be best for the fine filter? I'll have to ask BROKER about his setup.

What would be a good recommendation for a pusher pump?

I'm all ears, just watching to see what turns out to be the best.

Regards, Steve

11-07-2002, 11:23

I think what Choreboy was talking about doing was having some type of adapter made that allows you to connect the filter head/primer to a better filter. In other words remove the OEM filter, replace with adapter, then screw on the better filter to the adapter. At least thats how I interpeted it. It's an interesting idea, does anyone know why it wouldn't work?

11-07-2002, 11:42

Oh, I see what you're saying. I thought he meant unscrew the water sensor assy from the bottom and add another filter to the bottom of the stock filter.

It would be cheapest to find a better filter for the factory mount. If not avail., then I'd remove the entire factory mount and install another. I haven't looked at how that's mounted...

Regards, Steve

[ 11-07-2002: Message edited by: SoCalDMAX ]</p>

11-07-2002, 18:53
You are correct about my idea. Since the water separator does not seem to separate water from the fuel I thought maybe I can fool the computer into thinking everything is OK and put another type of fiter in the system. The water separator only has two wires which leads me to believe that I can either leave it unpluged or short it out and the system would not know the differance. Then I could put a CAT filter in the system by means of an adapter. I am looking into having an adapter made by a machine shop by using an old OEM filter and a CAT filter. I will also have to look into whether or not a CAT filter will be too much of a pressure drop on the fuel system which leads to SoCalDMax's observation.

If I was to add a pressure pump after the tank will it effect the already existing pump that pulls a vaccum from the tank. Does any major filter Manufacturer make a Pump, Filter, and Water Separator in one unit? That way you could could have the pre-filter and water separation in the system with no air bubbles. Also is there a replacement assembly made that will bolt-up to the factory system that way I would not have to use an adapter?

11-07-2002, 20:08
At the risk of opening another can of worms:


With all this talk about adding filters, keep in mind what Johnny "technician" might blame if you end up with a driveability problem. Best to keep anything you do completely reversible so if need be you can put it back just like the general delivered...

11-07-2002, 21:16
Just a stupid question, but, Why don't we ask CAT if they would make a filter for the DMAX? Not sure if it's probable that they would do it or not, but a possibility. Well, I guess this is my only way to get into this post since I'm not an individual well versed in diesel fuel filtration.


george morrison
11-08-2002, 07:31
LA Dmax; that is an excellent question, however, from my personal experience CAT pretty much denies the existence of any engine that does not have the CAT name on it. Even with all the potential market out there with the literal millions of Cummins, Detroit engines, CAT only makes 2 micron fuel filters for its own engines... CAT is missing a tremendous market, but, you have to know CAT to understand..

11-08-2002, 13:46
SWLA.... I think that would work, but you still run into the sensor on the bottom of the OEM filter. Could throw codes (has anybody disconnected the sensor and ran without it?) You would lose your 'water in fuel' light by removing for sure.

As for the adaptor... that would be fairly easy for a plastics molding company to do probably, but it costs $$$ to engineer a mold, and they would look at it from a standpoint of HOW MANY they could sell. A couple of hundred wouldnt justify the expense. ALSO, the adaptor would only work with one type of filter (fit). Some people might want a larger filter, etc., etc. Cant please everybody!

A secondary filter will more than likely be the way to go IMO, unless a racor or baldwin type company comes up with an absolute product that pleases all.

11-08-2002, 23:04
This is just a thought......what if we installed a filter on the return line. If the fuel is 60% clean in this line, would it be easy to clean it more? I know you would be starting over cleaning the fuel at every fill up. How much fuel gets pushed through the return line in one tank of fuel? If it was in this location you wouldn't need a pusher pump would you? Just some thoughts running through my head.

I would love to hear what Brokers fuel filter set is. Hoot....find out please.

11-09-2002, 01:27
Hello everyone, I may not have any room to talk but I've been following this topic for quite some time and will add my $0.02 worth. As my sig will show I don't, unfortunately, own a Duramax but have installed a primary filter on my 6.5. In its current config I have a 30 micron primary and the OEM (2 micron?) secondary. I did this to protect the lift pump and be able to remove water, if present, easily. I'm curious if having a "rough" filter would increase the efficency of the "fine" or OEM filter? I would be more that happy to provide samples for anyone that is interested in analysis. My personal take is fuel is probably the most variable and definitely the most consumed fluid in our trucks, why not do the best we can to ensure it is clean? I sincerely applaud George's work on the issue.


11-09-2002, 06:18
This is a great thread! Very thought provoking! Before it got started, I was ready to install a 2-micron (nominal) Baldwin DAHL 100 filter that I had bought for my 6.5 (never got around to installing it). I had decided to mount it ahead of the cooler and tap the steel fuel line using some Parker FERULOK flareless fittings and braided fuel line…. But now with all the good info being presented here I think I’ll heed JK’s advice and not rush into this.

JK’s point about being able to restore to the factory configuration and the issue of entrapped air has me thinking about the best method (and location) to plumb in the new filter. Also Steve’s following statement raises some interesting questions as well.

“3. Install another clamped hose to feed the pre-filtered fuel to a pusher pump capable of handling diesel fuel for 100,000mi and supplying 5-10psi at 10gph. The outlet of this pump would have the quick connect male fitting, to which the factory fuel line (originally connected to the tank outlet) would attach. This would pressurize the line from that point on and provide the correct conditions for the factory fittings. “

Are the quick connect fittings commercially available? What are the correct conditions for the factory fittings? Since the OEM pump can pull 60inHG, is the purpose of the low-pressure lift pump to reduce susceptibility of creating entrapped air?

Any other thoughts or ideas…?

11-09-2002, 08:09
I am not sure way installing another fuel filter is such and issue, meaning what to use and where to put it. The Ford and Dodge boys have been doing this for some time now. The big setup for the Ford guys is the Racor mounted on the inside of the frame. Hopefuly I will have the proto type mounting brackets Monday or Tuesday and we will be getting some filters installed so we can see the results.


11-09-2002, 08:12
Mr. Kennedy,

I see you mentioned the Preporator. I have been considering this installation. Quite pricey, but I sure this will take care of any cavitation problems, in which I know we are getting with our 25-30,000 psi systems. I am sure the air is creating the lack of lube problems we see causing pump and injector failures.

If and when I install this system I will keep you posted.


11-09-2002, 10:11
Greg, What do think is the best way to tap in to the fuel line?

11-09-2002, 11:10
This may sound dumb but why not
put a recirculating pump operated
filter to the fuel tank.The inlet
at one end -outlet at other end.

11-09-2002, 13:04

The holes on my C/C are right in front of the fuel cooler on the frame. I was thinking of making a C shaped bracket that fit inside the fram and extended up to the bottom of the bed. That way I could have more room to add my filter.

As for cutting my lines, I will. The service manager is a fiend and he said he didn't care. As a matter of fact he told me to keep him informed of what we were doing and he might pass it up to GM.

Someone ask if anybody made a filter and pump in one assembly and Stanadyne does.

11-09-2002, 13:46
Mr Plock
What I plan to do is cut the line with a tubing cutter right where we mount the filter. When I get the brackets and get it mounted I'll take pictures and show you. Just one cut so if you need to put the fuel line back together all you have to do is use one splice.

When you see the bracket we have you will not need holes to mount it, it's gong to work real slick, I hope. Sometimes the best laid plans don't work out.

11-09-2002, 13:49
What kind of lines are you going to use? I was going to use high pressure hydraulic lines for ease of fittngs.

What do the lines cost? And what do you think you will sell the bracket for?

11-09-2002, 22:49

To answer your questions, I'm hoping someone makes the proper fitting to install 3/8" NPT to QD fitting. I'm hoping to find it in a catalog somewhere. The reasoning for all of this (borrowed from a number of other sources including the Preporator website) is just as you said, to pressurize the fuel as close to the tank as possible to prevent cavitation and pulling entrained air out of suspension. I've been told it's never good for a pump to suck, the longer the distance and greater the suction, the worse it is for the pump's longevity. As expensive as this Bosch pump is, $150 for an extra lift pump might save a few thousand in the long run. The QD fittings were designed for a pressurized system, and could potentially leak air if used in a vacuum system, which this is.

I plan to install a sensor in the fuel line to measure vacuum before doing the mods. Then after the mods, I can measure pressure, post OEM filter, to ensure adequate fuel is flowing. I've planned it out so that if it all has to be removed, it can be without replacing anything, since nothing was cut in the process.

Regards, Steve

11-10-2002, 08:55
Do you plan to slip 1/2 inch ID hose over the cut steel lines and clamp on? Or would you use some flareless fittings like parker FERULOK?

I’m still learning here but wouldn’t the OEM lines and fittings be designed for some vacuum? As JK has pointed out, there is a shrader valve after the OEM filter for measuring vacuum (?). Also what are “QD” fittings? Are they the quick release types I see on the fuel input and return lines in the engine compartment (near the back of the driver side valve cover) that seem “loose”? Installing a vacuum sensor in the fuel line sounds neat, but could we also use the schrader valve port to check before and after performance with the added filter?


11-10-2002, 11:21
I was thinking of just sliding the 1/2" hose over the cut lines. A nice fitting would look better but will need to come up with something you don't need any special tools for. I will get out my Parker book and start looking. I like the idea of using the OEM fittings but finding them I bet will be hard.

11-10-2002, 12:10
My Parker book does not have the Ferulok fittings in it. The Aeroquip push on fitting might work well to.

11-10-2002, 12:29
Without going back thru every post on this subject to see if there is an answer to my question I am going to post the question I have.

I don't see what putting more than one filter in tandem with another will do if each filter has the same micron filter rating. All of the particles 2 microns or larger than 2 microns should be removed by the first filter if the filter is rated at 2 microns. If the Racor filter is changed at 15000 miles like the owners manual says then that is the best protection available until someone makes a filter as good as the Cat. filter.


11-10-2002, 13:22

It looks like our OEM filter only gets 40 to 60 pieces of dirt that are the two micron size out of a hundred. The addtional filter would get supposedly 98 out of 100 pieces of dirt. Togather they should get, just about all of it.

Seems simple huh?

george morrison
11-10-2002, 16:25
To follow on what Todd has shared, even if you had two filters of the same efficiency rating, roughly 50/60%, you would still cut the number of abrasive/5 to 10 micron size particles in half. These filters are rated in terms of efficiency, NOT micron rating alone. We always say a filter's efficiency relative to a micron rating. In our OEM filter, it is roughly 60% efficent at removing particulates. If we have the OEM removing 60% then on to a 98% efficient filter, we will achieve a very high level of cleanliness going into our pumps and injectors which is going to translate into very long life at optimum performance levels. George Morrison, STLE CLS

11-10-2002, 18:17
As you all know I have been keeping up with topic since it's inception. What I want to know is how are you going to install a filter after the OEM? I can't see coming up with a good solution of my own!!!

11-10-2002, 18:50
I found a description of the FERULOK fittings at www.parker.com/tfd/ and www.hoseandfittings.com. On the hoseandfittings site select Fittings - Steel - flareless hydraulic - straight or elbow 90. The 8-8 FBU-S is a straight 1/2 tube to 1/2 in NPT male. I'm not sure I want to go this way but it would make a good connection to the 1/2 steel fuel line and allow a way to connect the filter with high quality steel fittings and hose.

11-10-2002, 19:08
Got one more question. Can we buy the CAT filter head and filter and just install it someway in the system?

11-10-2002, 19:52
Thanks for the link I will look at it and see what they have.

Cat, Racor they both do a great job.


11-11-2002, 09:24
More filter news!!

Just got off the phone with the Sales and Marketing Manager at Stanadyne, Simon Garner.

He told me that their filters meet Bosch's Common Fuel Rail specification for filtration which is the same as the ISO TR13353 standard. The filter media is he same as Racor's. Racor just call's their's Aquabloc. The Stanadyne media is treated with a chemical that repels water therefore not letting it pass. Anyway it appears that the Stanadyne filter is the of the same quality as the Racor and I like the assembly better, plus it is cheaper and the elements are cheaper. Racor sent me a free 645R filter system and I am still going to use the Stanadyne, unless George and John come up with something better and I don't know what that would be better. Now if I could figure out how to place it into the system after the OEM.

11-12-2002, 22:01
To all of the knowledgeable members concerning the fuel filter testing; What is the best filter now available to replace the OEM ???? I ordered some of the INTERCEPTORS made by Parker, how are they ??


11-12-2002, 23:35

Yes, I believe they're called quick disconnect fittings, so I call them QD. They were originally designed for use with gasser fuel systems, which are pressurized with a pump in the tank. I'm told the reason that gassers can have a pump in the tank and diesels can't is the vapor pressure (volatility?) of each. Gas fumes displace all of the air(oxygen) in a tank. Diesel doesn't and can have an explosive mixture at certain tank levels. The pump may be a source of ignition, thus it's safe in a gasser fuel tank (unless the tank ruptures) and not in a diesel. The o-rings and sealing surface of the QD fittings were designed for pressurized use and may not always seal properly on a vacuum system.

The Ford guys have done a lot of research into this. A number of them have removed the fittings and replaced them with braided stainless hoses with swaged fittings or rubber hoses with clamps.

Regards, Steve

11-13-2002, 08:52
My 6-way valve for the auxiliary fuel tank is plumbed into my fuel lines inside the driver's frame (just realized that I have no photos in my links, have to fix that) by cutting the stainless lines and over-clamping rubber hoses. The fuel return line is clipped into the existing hose to the fuel cooler using the factory disconnect on the cooler. this system has worked very well for over 31,000 miles since end of December last year.

11-13-2002, 12:14
Your comment about the quick-disconnect (QD) fittings being designed for pressurized systems raises some interesting questions. On my 2003, there are QD's near the driver's side valve cover that connects the steel fuel lines to flex hose, but the connections to the OEM fuel filter uses hose clamps. The QD connections are easily turned and feel "loose". It would seem possible that they could leak under vacuum and suck air. Maybe the reason GM uses QD's in some locations and not in others is for easy of assembly on the manufacturing line(?) Do you think we could use the Schrader valve vacuum test port to check the QD fittings for leaks or should we consider replacing the QD's with a clamped or ferrule/fitting connection? If the clamped connection works for the OEM filter, it seems it would work for the other connections including an add-on filter - provided that a cut steel line was flared to provide a good seal to the hose. Or maybe a small amount of non-hardening permatex would seal a hose on an un-flared cut line(?). Since Tom's clamped connections are working well, I'm wondering if using a ferrule (Ferulok) flare-less connection to the steel lines would be overkill.

JK has pointed out that there is most likley only ONE filter and it's made by RACOR. All the other Filter suppliers just buy from RACOR and put their label on it.

[ 11-13-2002: Message edited by: jbplock ]</p>

Brent - DIS
11-13-2002, 13:29
Jomar posted 11-12-2002 09:01 PM
To all of the knowledgeable members concerning the fuel filter testing; What is the best filter now available to replace the OEM ???? I ordered some of the INTERCEPTORS made by Parker, how are they ??"


If you got an Interceptor with Parker on it you have the OEM filter.

Racor is a DIVISION of Parker Hannifin.


Interceptor is the name of the filter from Racor.


[ 11-13-2002: Message edited by: Brent - DIS ]</p>

11-13-2002, 14:16
Has anyone tried using a Davco 230 Fuel Processor?

11-13-2002, 14:35

The DAVCO filter looks interesting (http://www.davcomfg.com/) but I couldn't find any performance specs on their website. Do you have any more info?

11-13-2002, 19:42
There are some .pdf's and other info on their site. Now if they only had the filtration we are looking for...

"Laboratory tests and field trials show up to three times the life of "standard" diesel fuel filters. And at 5 micron rating at 98% efficiency, too. All this and it's made in the U.S.A. by Donaldson Filter Company."

11-13-2002, 23:23
I have been following this page from the begining and am consurned about this. I am currently working on making an adaptor like Choreboy and SWLA were talking about eariler for the Cat filter to adapt to the D-MAX fitting. I am a machinest by trade. A friend of mine has a PSD and is having fuel probablems and he and I are trying to work on this together. At this time I'm not having any probablems but am worried about the future of my truck. I agree with John Kennedy about keeping it reversable because if you on the road away from home johnny mechanic may not under stand.
I'll let you know the outcome of this project and hope to have it complete by the middle of next week or sooner. If any one wants to test the fuel after the conversion Im going on about a 3000 mile trip thanksgiving week and plan to change it before I leave and when I get back.

11-14-2002, 01:43
Would CAT make a filter for the Dmax? There isn't really any competition between the two makes in any area. I would think if they could make a buck they would do it. What better people to start a discussion than us. Literally thousands of customers right at their fingertips?

Matt B.

11-14-2002, 22:49
matt, I posed that question earlier to George and he said basically the only thing important to CAT is CAT and no one else matters, even if there is lots of money at stake in potential sales to Cummins and us for that matter they probably won't do it.


11-15-2002, 11:18
Has anyone looked into the Baldwin fuel filter? Might be different rating/efficiency as opposed to the Racor.
Descriptions : Microlite Fuel Element with Sensor Port
Fits : Chevrolet, GMC Light-Duty Trucks with 6.6L Turbo Diesel Engine
Replaces : GMC 97256734; Isuzu 8-97256-734-0
O.D. : 4 1/32 (102.4)
I.D. : 1 11/32 (34.1) & 1 1/2 (38.1)
Length : 5 5/8 (142.9)
Grommets : [1] Attached
O_Ring : [2] Included

11-15-2002, 12:21
Does the Duramax fuel system monitor flow or pressure downstream from the control valve (injector)?
If it does, then the pressure drop or flow rate across a filter membrane will prove to be less critical. The control valve will compensate for differing inlet pressures. The only time this could be affected (I think) would be in full open position. I would think that as a design criteria, the valve would never have a full open position. From a control standpoint, full open would assume "no control". Any thoughts?

11-15-2002, 14:14

I'm 99% sure that all the mfrs LOVE QD fittings because they can just be snapped on and no judgement need be made during the assy. process. I have another diesel and when it had a fuel line leak, it would "run funny" and the fuel economy was down 15%. When the leak got really bad it needed to be reprimed every morning just to start. This phenomena might account for the different economy numbers all diesel owners are seeing, in addition to all of the other obvious factors. Some people's fittings may be sealing better than others.

I figured rather than fool with all of the fittings, I'd kill 3 birds with one stone and add a lift pump and pressurize the system.


The ECM must be monitoring either vacuum or fuel rail pressure, because if your fuel filter clogs to a certain level, the engine goes into limp mode and won't rev over 2,000rpm along with an SES light and code. If it's monitoring fuel rail pressure, that means the pump has been struggling to get to proper pressure and failing to do so. I don't like the thought of that.


There's a local co. here that CNC machines any kind of teflon, nylon, polycarbonate, etc. If we can supply CAD dwgs or even a napkin sketch and the 2 different filters, they can make an adapter for a reasonable price, considering the qty involved. They are meticulous and if it's not perfect, they eat it and do it again. Plastifab is the name, Phone # is (858) 679-6600.

Regards, Steve

11-15-2002, 15:05

The Baldwin filter is a purchased part, meaning they buy it from Racor. This would explain the less than competitive price...

11-15-2002, 16:07
New Stanadyne filter installed today mounted on the frame.

Pics available soon!!!

11-15-2002, 21:03
Do you think the Wix filter is also a Racor?

The fuel filter is part #33810 by Wix, $40.02, @MurraysDiscount.com

11-15-2002, 22:50
I'm sure they are ALL purchase parts as the filter itself is so goofy looking I am sure nobody has tooled up for it. Looking into adapting a different filter to the OE mount, but then the water sensor will no longer function...

11-18-2002, 11:48

I wonder if the water sensor actually does function?

Regards, Steve

11-18-2002, 11:55
I'm sure if you had a large slug of water hit the bowl it would work, BUT the engine vibration would tend to break it up (as happens with tank slosh), AND water seems to find it's way through the filters anyhow.

Kind of a Catch 22 as you pretty much NEED the sensor for liability and to keep the mfr off your back...

11-18-2002, 13:30
I have proof that the water seperator works on the factory filter. They say a picture is worth a 1000 words. If you want a pic of the inside of a factory filter then e-mail me at:


01-09-2003, 08:57
I called Racor tech yesterday to start from scratch on this for my own edification.

The tech I got told me the GM oem filter comes from them at the same spec, just different paint as we already believe.

I asked about an in-line and was recommended a 660R2 assembly with a R60S replacement filter cartridge. Said this was a 2-micron.

I haven't been able to check the website to know if this is up-line or down from the 645R but the tech said I would probably never need to change the oem filter but it would be prudent to do it every year or so anyway, depending on miles.

george morrison
01-09-2003, 09:10
Looking forward to reviewing the results!

01-09-2003, 09:12

Yes the Racor 660R2 is a good choice. The 645R is a bit smaller but works just as well. One thing the 660R will do for you beside more gph capacity is longer filter life as well.

We have got a lot of guys using both the 660R and 645R. You could even go with the big boy 690R but mounting is a bit tuffer do to its length.

01-10-2003, 04:02
Todd- My Racor dealer is also the Stanadyne dealer in my area and the 100 series filter assembly we were comparing to the Racor 660 was almost double the initial cost.

We must have done something wrong in the cross reference. The discounted Racor assembly was just over $80 with the replacement element $21.

I don't like ferrul type fittings. For a $40k plus truck I don't want to save a few bucks on the installation of the filter. I will probably interrupt the fuel line where I have plenty of room to work and run a braided SS line to the filter mount and back. The brake line type flare with brass fittings works well with extreme pressure levels and is easy to connect/disconnect.

[ 01-10-2003: Message edited by: TraceF ]</p>

01-10-2003, 04:43
I'm no expert but I did a little research a while back and found that brass ferule fittings are designed for "soft" tubing like copper and aluminum and are not recommended for steel tubing. I went into my local NAPA and they had the weatherhead brass ferrule fittings next to the steel brake lines. The label on the drawer specifically said not to use with steel tubing. Parker makes high pressure "Ferulok" fittings designed for steel tubing that "bite" in to the tube making a positive seal (a Brass ferrule is softer than steel) I once tried to use brass ferrule fittings to mend a transmission cooler line and it leaked. I ended up using hydraulic hose.

01-10-2003, 06:32

Thanks- come to think of it, the brake line fittings I used on my CJ build up were in fact steel. Good catch Bill.

01-10-2003, 07:40

Your dealer must be high on diesel fumes, just kiddin. The FM-100's price with the optional hand primer is about $90. The is with a element. The replacement element is only $12. Besides the Racor 660 does not have a hand primer, so you must fill the filter with fuel, pain in the a**. Also the FM-100 is modular, you can add on to it later if you need to etc: fuel pump or heater. On the Racor you would have to buy another whole unit that had that on it.

Here is a link to my installation. I just slipped 1/2" braided fuel line over the fuel line and put two clamps on, no leaks.

a bear
01-10-2003, 08:12
Bill & Tracef,
We use Parker and SuageLoc compression fittings (nut & ferrule)type for 1/4",3/8" and 1/2" safety systems applications here offshore. The working pressure for these fittings are 11,000 PSI. Once you install these fittings they are there to stay. I have catalogs out here with prices and vender names that stock these. If this info. would be helpfull let me know and I will post it later today. :D

George Gozelski
01-10-2003, 23:42
Hey jcopeland, you my man have hit the nail on the head! I am interested in what you are doing, keep us posted after your trip!

Why can't Racor put 2 micron filter media into the oem filter and call it good? Seems like a simple fix to me rather than adding another filter setup! I would be most interested in jcopelands setup rather than adding the additional filter housing! ;)

01-11-2003, 05:02
The reason they don't put good media in the OEM is because GM is not paying for the good media. The 2 micron Racor element filters as advertised. We are getting very close to having a fix that is simple and easly installed and will use a Racor 2 micron filter.

01-11-2003, 07:49

Just because GM isn't paying for it as an OEM doesn't mean they couldn't make one as an aftermarket. Unless GM has a contract stopping them??

01-11-2003, 10:35
Well this all has me so confused, I would like to use the best filter in my existing housing and not add another. If there is a better filter than the one I get from my GM dealer that removes more dirt from my diesel fuel could someone simply tell what the best replacement filter is??


01-11-2003, 10:51
All current filters for the Dmax are from the same mfr. I would hazard a guess that you will see few, if any additional mfr's step up and build their own due to the specialized nature of the application.

SO, if you want improved filtration, it would be best done with a secondary filter IMHO...

01-11-2003, 10:55
Todd- you may be right about the fumes. There were lots of series 100 fuel filter assys, is there a more specific part number or is the FM what we need? I'm in Central FL so I don't need a heater but the primer would be nice. Does the replacement filter at a $9 savings last as long as the Racor? I'll try to cover this with the dealer in more detail. I do not see the link to the pics. E-mail it to me Todd, I will send you the pod pics a little later.

a bear- Thanks, please post the additional info.

George G and Bruce C- Racor tech told me the oem filter was 2-mic media. Was I misinformed?

[ 01-11-2003: Message edited by: TraceF ]</p>

George Gozelski
01-11-2003, 12:47
Seems rather odd to me that the "aftermarket" filter people can't build a replacement type oem filter that contains the good filtering media! I'm not going to wait around forever for someone to come with a good filter, nor do I like the idea of installing another filter setup in an already "overcrowded" engine compartment. I like what Jcopeland has going, I'm going to wait and hear what he has to say. Personally, I'd pay to have a new "CAT" filter head machined to fit my Dmax, all that's left then is to slap on the CAT filters (possibly minus the water detecting device)!

01-11-2003, 15:38

Here is the link. I guess I forgot a step in last post.

The FM-100 should last long enough. I change mine with the oil change. Evdry 5k. If we can wait, I will answer all of these questions about the FM-100 very soon. I am working directly with Stanadyne to get this issue resolved.

The additional filter goes in front of the fuel tank. It is not crowded there.

01-11-2003, 16:25
srubrn- Looks good! Thanks in advance for the follow up on the Stanadyne.

01-11-2003, 17:26

I hunt just past you in Nanafalia, AL

Maybe when you get all the kinks worked out. if b4 the 31st of Jan. I can stop by and have a look see. I live about 2 hrs South of you in Slidell,La



01-11-2003, 17:29

That filter pic is a good argument for EMULSIFYING water! It doesn't all get stopped by the filter, and if it is left to stand in the injection system...

As for the aftermarket and filter systems, I can only speak for myself by saying that it will be a little while yet, and I will not be price competitive with the Racor/Stanadyne stuff. Unique, yes, quality, yes, but more $$$.

01-11-2003, 17:36

Is Slidell down the La peninsula near Cypress Cove? I am trailering out there in June to Tuna fish.

We'll be at CC for a week.

01-11-2003, 17:42
Okay Devil's Advocate here

Why is everyone in such a pain about fuel filters.

So far there is no proof of a problem, is there??

Maverick is over 100k on his truck and Broker has how many trucks with how many 100K+ on them and hasn't had an injector problem.

Are we creating a problem so we can worry about creating a solution???

Don't get me wrong, I'll be in line to buy a easy attached system from someone like Kennedy if he has one that works but I'm just wondering why everyone assumes it's needed.

01-11-2003, 21:55
There are several cases of injector failure already due to dirty fuel. It usually happens aroun 100k. Right after warranty.

As far as broker is concerned I believe he either double filters or triple filters his. It was in another post.

The factory filter already has proven to be on about 55 to 60 percent efficient and a set of injectors are about $5k not including labor. A good $90 filter set up will solve the problem and it sure won't hurt anything. I have been running one for about 5k now, no problems yet.

01-12-2003, 09:02

You can come by anytime. I am sure the kinks will be worked out soon. You can still see the installation. Shoot me an e-mail. I work on even numbered days though, 24hr. shifts, except for Friday's.

01-12-2003, 11:56
JK,how long till your solution is ready?

01-12-2003, 12:11

Not sure yet. I need to get my analysis back and see how we did and if we need to address any other issues. Hoping to get a couple more prototype units run off soon. My plan is that the OE filter will take the brunt of the load and the secondary will be very large offering minimal restriction and long life due to excessively large holding capacity. I'm figuring a guy will change the OE unit at the regular intervals and the secondary unit annually or bi-annually. While the unit WILL have a drain for water/service, it will still be my recommendation to use an emulsifying additive to ensure that water does not settle out or absorb into the media.

01-12-2003, 14:33

That would be cool. I'll shoot you an e-mail this thurs. I'm heading up that way Fri. b4 noon and coming home sun. 10ish a.m.

01-12-2003, 15:37
JK,will the FPPF Total Power and cetane booster blend I use emulsify the water sufficiently?
I know there has been a lot of talk here about what product or products work and don't.
I'm using 2 ounces of each per 26 gallon tank of fuel.What do you think? Blake

01-12-2003, 17:54
I am still not convinced either way on demulsifying or mulsifyng. Is that how you spell that? I like the idea of demulsifying the water and it never getting to the engine. But does this actually happen with the additive? It's been explained to me and I just can't seem to decide!!!

01-12-2003, 18:39

All is dependent on the amount of water. I use Fuel Power (foundation of Total Power) is capable of tying up it's equal in water. You can basically mix it at 1:1 with water and NOT detect the presence of water with water finding paste.

Free (demulsified) water is undoubtedly a bad thing. It just doesn't make sense to settle the water out, then shake it back up and then try to settle it in the filter. :rolleyes:

jcopeland has seen first hand how water can breed bacteria :eek:

The FPPF recommended treat ratio is 1000:1 or .128oz/gallon. I run 1.5x the recommended treat ratio, or .192 oz/gallon which comes out to just shy of 2oz/10 gallons filled. I generally just put in 4 oz or so per tank. Used regularly, the fuel system will stay fresh. There's really not much you can do about excessively large slugs of water, but if you practice good housekeeping, there will be far less chance of problems. In the event of a large slug of water, a guy could use Fuel Power which is VERY inexpensive, and highly concentrated.

01-12-2003, 18:49

Let me know when your system is available. I'll be a buyer.


a bear
01-12-2003, 21:34

I took a look in our Parker Cat. and found the fittings.(unfortunatly no prices) Our inst.tech. said they run about $6 each. I think they would run a little higher than that. They are made of 316 stainless steel. If you're still interested you can go to the Parker Hannifin site and look in the instrumentation section (CPI Fittings)

01-12-2003, 21:52

Why do so many OEM recommend Stanadyne if it is bad for the system? I don't understand why the filter won't capture the water with the chemical in it. I will be running a test to find out. Both ways. One with total power and the other with Stanadyne. Or just use nothing and let the two filters get the water out, the media is supposed to not let waterpass.

01-12-2003, 22:51
I orginaly built a filter adaptor that would screw in the place of the OEM adaptor and used the CAT filter in it's place. After talking with John Kennedy about this he talked me into using my OEM and my CAT filter. If I was to get a large slug of water in my fuel I would not know It until it was too late. Which made sence to me. By the thanks for the help John.
I then made an adaptor that would work after the OEM filter using the CAT filter. I sent my fuel to the lab and had it checked before and after the before particle 4651 &gt;2um the fuel after both filters was 7081 &gt;2um which blew my mind. Then I talked with George Morrison (thanks for all the help George) and John Kennedy about algie build up's and that was the conclusion we came up with. I've been running an algicide (if that's how you spell it) sence then and ran another test last week. The particle count was a hole lot better we also ran a microorganism test and it detected some slight fungal growth still in my fuel but the particle count was 494 &gt;2um a hole lot closer to the target which is 320 &gt;2um.

To sum it all up were getting real close to what we are looking for. From now on I will be using an additive in my fuel because I never suspected and algie grouth until I had the test ran.

George Morrison can explain the test results better than I can.

Sorry about the long write up.
Johnny Copeland

01-13-2003, 09:10

Stanadyne was the OE fuel injection pump mfr. for GM since 78? when the 5.7 came out. If they give the additive their blessing, so must GM.

I guess I'll put this into football/prison terms with the Super Bowl coming up:

You can play zone defense or man defense. You can shackle and assign a guard for every prisoner in a crowded downtown shopping center, OR you can let them run free and turn them all back at the "detectors" at the doors.

I know the way that I would run this system...

Emulsify it, lock it up, and rest easy, because if it gets past the first, and only line of defense and it settles out further downstream, it can cause serious problems just like the inside of that fuel filter in the picture :eek:

george morrison
01-13-2003, 09:27
To continue with John Kennedy's discussion, Stanadyne builds water separators. Thus the fuel additive they produce contains a water demulsifying agent to promote free water settle from the diesel fuel. All diesel fuel has some level of entrained water in it, as you have seen from the published fuel analysis results. Thus, by using a demulsifying agent Standyne's rudimentary fuel separator can work more efficiently. However, as John Kennedy has shared, the water can then separate anywhere in the system, including the fuel tank, separator, pump, etc. Free water is our enemy; this is what can scar a fuel pump in a heartbeat. Emulsified water can pass through our fuel system without causing harm as the water molecule is surrounded by lubricating agents/diesel fuel.
CAT has been working with water emulsifed fuel containing over 500 ppm water as a possible "clean fuel" alternative. It is still in developmental stages and has real world operatoinal problems but not related to fuel injector/pump life, primarily performance issues.
My position of "locking up" water, emulsifying it chemically, is from years of living with diesel engines, having to approve the exchange of $18,000 fuel injector units, etc. due to free water damage.. Plus, by locking up the water we minimize the problem John Copeland recently experienced with the microbe/algae contamination as one must have free water for microbes/algae to grow in. By locking up every water molecule, we essentially have a bacteria stat condition. Instead of having to use bactericides (poisons) we achieve the same end..
Plus effective injector cleaning, corrosion preventive, lubricity enhancement, cetane boost, and of course agressive emulsification, etc..
Both FPPF and Primrose 405 contain all of the above.

a bear
01-13-2003, 19:04
John / George
Wouldn't emulsifing fuel cause a thickening / degrading problem if a large amt. of water is pumped into the tank. My point is, most people would pour the additive when fueling up. By not being able to see what your pumping you could introduce large amounts of water without knowing. Then you would have to clean heavy emulsion out your entire system.

For some reason I always thought a good setup would be for the main tank to have a drain sump with electrical monitoring there. Then if a demulsifier would be used the tank would be a place where maximum retention time for break out could occur for water removal.

I was also thinking of another set up on my tank that would use a non vented fill cap. and install a different type vent that would use triethelene glycol to remove The dust and moisture entering the tank. I am sure a lot of dust enters the tank through the tank vent due to the low vapor pressure ofb the fuel.

Your comments on this would be appreciated

01-14-2003, 07:50
a bear-

This is the question haunting me too and the reason I am going with the 2-mic filter before the oem filter. I have dual Racor fuel water seperators on my boat, one for each engine and I get fuel at some places that slams the bowls on the bottom of the filters full.


What happens in the engines system when the emulsifyer carries it through? Will we have 300 miles of poor performance? It seems like this would be more detrimental on something as sensitive as the Dmax fueling system and not so critical in some of the larger equipment mentioned.

george morrison
01-14-2003, 08:30
If one gets a 'slug' of water even an emulsifying additive is not going to be able to handle that level of water and it will be captured by the water separator to the degree that it can. However, as a normal course of operation all diesel is going to contain 60 to 100 ppm of water. When diesel fuel is allowed to sit dormant, mother nature/gravity takes over and the entrained water will begin settling out; anywhere in the system. The vibration from just starting the engine and letting it idle will cause the water to go immediately back into loose emulsion. This process occurs again and again throughout the fuel system. By chemically "locking up" the relatively small amounts of water always present, we ensure that free water does not occur anywhere in our fuel system. Thus we eliminate the "potential" of free water damage plus have eliminated the source of microbe growth. The 'locked up' molecules of water are now surrounded by a lubricating cover (this is what an emulsion is) which allows the water to go through the system without harming our high pressure pump interfaces or injectors. Along with providing additonal lubricity, corrosion prevention, cetane boost, etc...

Water content, unfortunately, has become a reality due to the EPA's declaration that diesel fuel tank bottom water is hazardous waste. Diesel fuel vendors have dealt with the disposal costs by not drawing bottom water from the tanks regularly. So diesel fuel containing relatively high amounts of water and microbe contamination is almost the norm, depending on the station.
Using a small amount of emulsifying fuel additive is a very inexpensive insurance policy against some potentially very costly repairs.

01-14-2003, 12:15
John and George; I recently talked with my service advisor on his dealings with GM on the Dmax fuel filtering analysis and two things came out of it. First, GM recognized that the re-engineering study with Racor was ongoing but would not provide a date for completion or any type of pre-TSB notification to prepare the dealer network to handle service issues. Second, this dealer recently warranteed a set of injectors on a &lt;36k Dmax, with no evidence of contaminated fuel. Apparently they are not the only dealer that is seeing injector failure well before the 100k powertrain warranty; and this is helping to push GM in a positive direction to solve the problem before the "market" understands what a serious problem this is from a reseller standpoint. He suggested that I continue to monitor the ongoing testing and provide the results so that he can "back-door" it through the service network.

George Gozelski
01-14-2003, 13:09
Hey Jcopeland, how do have your CAT filter set up? I take it the CAT filters aren't set up with any sort of water sensing or purging device?

I have more concern than any of you other Dmaxer's due to Alaska having the dirtiest fuel in the nation! That being said, you can probably understand my concern. It sounds like you have a good setup going, am REAL interested! :D

01-14-2003, 15:11

Thank you for your input. Up until now, we've only been speculating/making educated assumptions based on the past experience of others like George. My analysis will be completed any day now and provided there aren't any irregularities like Todd's or Johnny's, we should see how well my prototype unit works. I tried to clean things as best I could before installing, and tried to get as pure a sample as I could, but the prototype mount is missing one procedure that will be implemented, should any production units be built. Time will tell..

01-15-2003, 00:03
FirstDiesel wrote:

&gt;Okay Devil's Advocate here
&gt;Why is everyone in such a pain about fuel filters.
&gt;So far there is no proof of a problem, is there??
&gt;Maverick is over 100k on his truck and Broker has how many trucks with how many &gt;100K+ on them and hasn't had an injector problem.
&gt;Are we creating a problem so we can worry about creating a solution???
&gt;Don't get me wrong, I'll be in line to buy a easy attached system from someone like &gt;Kennedy if he has one that works but I'm just wondering why everyone assumes it's &gt;needed.

srubrn wrote:

&gt;Firstdiesel, There are several cases of injector failure already due to dirty
&gt;fuel. It usually happens aroun 100k. Right after warranty.
&gt;As far as broker is concerned I believe he either double filters or triple
&gt;filters his. It was in another post.

In his 01-11-2003 post BROKERS writes:

01-15-2003, 06:14
George Gozelski, I am running through my OEM first and using it as a water seperator and it also has the water detecting device to let you know if you have any water in it. Going out of my OEM and straight into the cat filter using an adaptor I built, then into my fuel system. It's a plane clean setup and with the lab results it's proof it is working. I consulted with George Morrison and he said to keep running my additive and make one more filter change it there should be down to our target, and also no more lab reports should be needed.

01-15-2003, 08:00

You didn't read enough and I can't think which post it was about Broker. He does double or triple filter his fuel. He has aux. tanks on all his trucks with a fuel pump on them and then it goes thru a filter before it goes to the OEM filter. Also if your read a couple of post above this you will see there are certainly problems with injectors. Ask George about the pictures thru a elctron microscope of the inside of the injectors, he said it looked like the craters on the moon. Besides if you really don't believe it, $90 is cheap insurance for a $6000 injector job.

Everyone else,

I am sending a fuel sample out today testing once agian the efficiency of the Stanadyne FM-100 filter. Will let you all know the results soon. Actually I am send two sample to two different places, one being George Morrison at AVlube.

01-15-2003, 09:44

Are you using the CAT 1R-0751 filter (2 micron, high efficiency) with no lift pump and mounted underneath the cab on passenger side?


01-15-2003, 09:45
I haven't seen the actual paper printout, but George just called and said we hit our goal of 15-13-11 !

In actuality, we are VERY close to 14-12-10 as we have:

15 169ppm vs. 320 spec (need 159 for 14 rating)

13 56ppm vs. 80 spec (need 40 for 12 rating)

11 10ppm vs. 10 spec (needed a 9 for 10 rating)

The prototype mount was not yet anodized. Anodizing should ensure that any free metals from the machining process are burned off or tied up so they cannot work free.

[ 01-15-2003: Message edited by: kennedy ]</p>

01-15-2003, 15:41

From the sound of it, your filter is going to cost more than a set of injectors, just kiddin. Keep up the great work!!!

01-15-2003, 17:29
Question of economics-

If a 2-micron filter in-line before the oem filter at an initial cost of about $110 with a element replacement cost of about $12 is improving filtration by a factor of- say for purposes of the question- a factor of 2...

and consequently the oem replacent filter is expected to last at least twice as long (hypothetically) at a replacement cost of about $56 according to my dealer...

will the efficiencies from an economic standpoint support all the extra expense of going post oem?

My assumption is that the assembly will be costly as will the replacement elements and we know that the burden of the filtration will remain on the already costly oem as primary.

Now I know someone is going to say "if it saves you $6k injectors, etc, etc, etc".

I guess the real question is how much insurance am I really willing to buy? I think the 2-micron in-line primary will be very effective compared to the oem.

Can't wait to see the forthcoming test results on Todd's Stanadyne.

[ 01-15-2003: Message edited by: TraceF ]</p>

01-15-2003, 19:16

My FM-100 was only aobut $90 and the OEM filters are only $20 from Kennedy.

Maybe this helps.

01-15-2003, 19:29
I got some information from a Detroit Diesel shop today about Davco Manufacturing. They sell
fuel filters for Detroit and other diesel engines.

I went to their site tonight and found that they claim to make a filter that works to 2 microns.
Here are the links it does have an interesting demo they do on there site called "Seeing is Believing"

Home page: http://www.davcomfg.com/pages/home.html

filter model 232:


Just wondered if George has any info on this or if anyone else does.


01-15-2003, 19:43
Economics will not be a major factor here. The cost will be in the mount/filter assy for the secondary filter which should last a year or better. Element cost will be reasonable as well and in the $35ish range. The OEM filter service intervals will remain the same.

a bear
01-15-2003, 20:21
The test results sound good. Are there any pictures of the prototype? What kind of secondary
filter are you using? I'm kinda coming in on the tail end of things and couldn't find your filter info.in the search.

My filter installation is on hold. Was kind of waiting to see how all these ideas would shake out. :eek:

01-15-2003, 21:08

Thanks for the correction. I hope John will be able to put a
package together, cuz he'll have a new customer once
it's ready.

01-15-2003, 22:36
a bear,

Can't disclose the details just yet as they are not set yet. I DEFINITELY will not set a release date judging by the critical nature of this crowd :eek:

01-16-2003, 00:03
Hey John, if you need a Beta tester out here running this Sweet California (Dirty) Crude, let me know. I know you have a short list of "locals" standing in line back there, but for Nationwide Coverage you gotta branch out LOL smile.gif


01-16-2003, 06:12
Im using that filter but it's mounted under the hood with no lift pump and have had no probablems with it.

01-16-2003, 15:29

Sorry, I didn't see your post.

CC is many miles miles from here About a two hour or so drive.CC is at the end of hwy 23 in Venice La. and has some awesome charter Boats that can put you on the Tuna, especially if you go out at night. Slidell is where I-59 I-12 and I-10 meet. about 15 miles northeast of New Orleans and 10 miles west of the southern-most west border of Mississippi. You will have to pass through Slidell to get there coming from Fl. Are you hauling your own rig down or are you chartering. If so with which Capt. I enjoy an occasional trip outside but mainly run my Bay Boat around the shallows of Delacroix for Specks and Shell Beach for Reds. You can't beat fresh Tuna (we try to eat it all in about a weeks time). Once you freeze it it's just not the same. They are slaughtering the specks down in empire right now in a few choice areas.

Shoot me an e-mail b4 you pass through.

01-16-2003, 16:04
pepperidge- Taking my own boat. :D

Not much into spec fishin but love the striking fish and agree with you on the tuna steaks.

I put CC and Slidell together because of a boat dealer ad. Maybe he has a branch in Slidell.

Thanks! smile.gif

01-16-2003, 19:33

Keep us informed. I for one am interested in your solution to this.

01-20-2003, 20:37

I am very interested in the arrangement you used to adapt the CAT 2 micron filter into the DMAX system.

Please e-mail me at skih2o@carolina.rr.com with further detail.

Thanks and regards,


01-20-2003, 22:22

Would you please email me at


I am very interested in your CAT filter
hook up.

I have been trying to find time to visit CAT here and see just what they had to offer in
using their filter between the OEM filter and the pump.


01-21-2003, 09:24

Would appreciate an email from you on CAT Filter location. Email Ld1440@wmconnect.com


01-21-2003, 10:02
On 10-28-2002, george morrison posted:

&gt;I wish we could post photos on this site; I have an
&gt;electron microscope photo of an injector at
&gt;95,000 miles that looks like the lunar surface.
&gt;All due to dirt. Our high pressure fuel systems are
&gt;very susceptible to ultra fine particulates. We are
&gt;calling it 'dirt' but it is really ultra-fine contamination. :eek: :eek:

So every time we take a trip....... I have a mental picture
of this "sandpaper" fuel easily passing thru my filter and
scoring my injectors. Not a nice thought. :mad: :mad:

I thought for sure that with this long Holiday weeked, John
Kennedy would have figgered out how to solve the problem
and have his unit for sale to us. :D :D

01-21-2003, 11:05

I have 3 different machine shops doing bids/prototype mounts, but until I get a couple more out/installed/sampled and can prove repeatability in the handws of others, I can't say much...

01-21-2003, 14:47
Well I am waiting on a fuel sample now that I sent directly to Stanadyne from the FM-100 on my truck. If it checks out ok then I am going to send a second sample to George Morrison that I took at the same time to qualify the results. For all of you on the side lines chomping at the bit, hang on, results are near.

01-21-2003, 19:32
Schwing! Music to my ears!

01-23-2003, 21:09
Got back some results today and it was not exactly what we were looking for. It's possible that my sample taking technique is the issue. After talking to Stanadyne's engineers, we have a way to take the samples that should give us the results we want. I am taking the samples again tommorrow after I add a little more hardware to the filter setup to better facilitate the sample taking. I feel very confident that the filter is fine and it is my technique that is in question.

02-05-2003, 22:11
found this item interesting saying the Baldwin fuel filters are now better than Cat:



02-06-2003, 01:52
Well it is almost midnight and I have re-read this entire
string....... whew!

I had over-looked Todd's picture of his set up.............
It looks like a reasonable solution.

Todd, any more results since you last reported on 01-23-2003?

02-06-2003, 08:20
The Stanadyne filter is a very good quality unit. The Racor is as well. I have duplicated Todd's installation with minor differences. Todd has forwarded me the test results and I intended (still do) to get our lab to give me some comments and ideas but I have been traveling and not given this any attention. If we can add anything to the interpretation he already has I am sure he will share it.

I installed my 2-mic unit at about 5k miles and replaced the oem at the same time. When I open it I will report the findings. After 5k more miles I will open the oem filter again.

I know this isn't very scientific but I am only trying to accomplish a quality prefiltering of the fuel and I think Todd is on the right track with this.

E-mail me if you would like to see pics of the installation.

02-06-2003, 11:02
The Baldwin article is dated Feb 17th 1998
Do they make a filter that will be small enough yet filter to 2 mics that we can use on the Dmax?
The fuel filters that I have seen on the Cat aps are huge.

02-06-2003, 12:12
Have you seen this one?


:eek: :eek:

02-06-2003, 12:18
For the people who are trying to put a fuel filter downstream of your oem filter try looking under your Air Filter for room.

I have a 2001 D/A and I had enough room to mount a Racor 490 Series System under my Air Filter Assembly. The filter pushed out on on the plastic inner-fender a bit but I don't have large tires that rub. I also had to modify the bracket that holds one of the horns in place.

Now when I replace the filter (hopefully long intervals) I take out my right headlight and prime the filter.

Hope this helps somebody. ;)

a bear
02-06-2003, 18:45
The fuel filter and results look good. I'm sure a lot of thought went into the mounting location, hardware, media type and what not. I will definitely be at the front of the line when its available. Hopefully still in Feb. Looks to me like you completed all the homework. Sure saves me the time and headaches. :D :D :D

02-06-2003, 19:16
John, where does the line start? smile.gif This is a "must have" for me. Thanks for all the hard work you do for us, along with many others here!


02-06-2003, 20:02
Dear George and John,

I can't bear to re-read this string again. :confused: I'm excited that
John is almost to production... but could both/either of you
tell us (again) or summarize why you believe "post" filtering from our
original equipment is better than "pre" filtering as Todd
and Trace have done.

John, you wrote " Economics will not be a major factor here"
To a non mechanic, it would seem that a "pre" filter
with a 2 micron filter and a cost of $12 to replace would be more
economical than replacing a $35 "post" filter even if you have
a one year life span on it. I'm not trying to be critical..... just
looking for the best way to treat my truck.

Thanks much smile.gif

[ 02-06-2003: Message edited by: 56Nomad ]</p>

02-06-2003, 20:25
I wanted it AFTER the factory unit so we would still service the factory unit, and the factory water in fuel light would see the water first. By installing as a secondary unit, we are only cutting hose which can be easily reversed.

While not necessary, I will be replacing the short section of hose from the Bosch EDU to the filter unit, and routing the outlet down to my secondary unit. This way all of the substantial lengths of the OE spongy hose will be replaced. I'm not sure if we can get away w/o rotating the factory outlet nipple, but I rotated mine.

I've been told that the filter unit I am using is actually a fraction of a percentage point more efficient than the other units mentioned above.

General production of the mounting kits will likely be done by a DP Member! The finished units will be anodized and likely electro polished to remove any microscopic surface "fuzz" which was not done to my prototype. Hopes are that the sample results from the first prototypes will back up my results!

BTW, we are still at least a couple of weeks away from any production as I am still working out a few details.

02-06-2003, 21:25

you wrote: "I wanted it AFTER the factory unit so we
would still service the factory unit, and the factory
water in fuel light would see the water first. By installing
as a secondary unit, we are only cutting hose which
can be easily reversed."

Lets assume that we deal with the water issues with
quality fuel additives. As a secondary unit, the "pre-filter"
installation can also be easily reversed. Perhaps, I am
viewing this too simplistically, but basic question is....

Can a "pre-filter" work as effectively as a "post-filter"?
This would be in respect to filtration as well as required flow pressure

02-06-2003, 21:51
I guess a pre filter could, but if a big slug of water hits my filter you will not know it. I'd prefer to let the OE filter sort out the "sticks and stones" and maintain it at the recommended intervals to keep GM's shorts out of a bunch, but if you'd rather plumb it this way, go for it!

02-06-2003, 22:47
I would have some fuel sample results for ya'll by now if UPS had not have lost them. I am going to try and take some more samples tommorrow. It takes about a week to get them into the lab. Unless the results show otherwise, I am still happy with my installation of the Stanadyne FM-100 "2 micron pre-filter".

Funy thing happened though. I took my truck in to get the balence rate checked on my injectors and the tech II, just said THANKS.

02-07-2003, 05:01
RWTD er um Srubrn,sorry..... :D

J/K couldn't help myself.....

Waiting patiently for your results......We do appreciate the leg work....

MAC :D :D :D

02-07-2003, 08:06
mackin- I always get a grin out of your posts. Sure wish I knew what code you speak sometimes though.

Comments on the past dozen or so posts- I can easily check for water in the see-thru bowl of my filter be leaning over and looking from the passenger side and it's a lot easier to drain than the oem. If a big slug of water were to get by it which is very unlikely, the oem water sensor will still say so.

Close inspection of the fuel line I cut shows that it has a flex hose on both ends and could easily be replaced at any time.

My goal was to have a quality in-line prefilter to keep me from dealing with the oem unit as often. For about $130 including hoses I believe this goal was accomplished.

The only other modification I will make and recommend to anyone taking this route will be to make a mini guard if you go off road. I am thinking a pipe hoop with two flat tabs I can bolt through the bottom of the frame rails.

By the way- the pics I saw of JK's assembly are way cool and there is no reason why it couldn't be pre-oem if you can find room for it under the truck. I considered putting mine in front of the fuel tank where there is more space but the Stanadyne unit is small enough I was OK with it on the frame rail and I didn't have to spend any time designing a mounting bracket.

george morrison
02-07-2003, 10:51
I am going to get a bit esoteric here but another reason I like John Kennedy's setup is that John's post filter serves as a wonderful dampener for the harmonics that back-feed through the fuel from the injector/pump firings. These vibrations act like an ultra-sonic cleaner for the fuel filter/water separator. CAT experienced this when they changed from a 20 micron to a 7 micron absolute fuel filter to capture the 7 micron particle size. The 7 micron filter did not capture a significant amount due to the backfeed harmonics. Thus CAT had to switch to a 2 micron absolute (beta 200) to achieve a 7 micron beta 200 level cleaning. So, we should have some synergism here with John Kennedy's setup. By dampening the injector backfeed at the first filter, our OEM filter/water separator performance should be enhanced appreciably as it is going to have almost lab conditions to work in and not ultra sound cleaned constantly. At minimum, the OEM ultra sound should be minimized.. This will also enhance the water separation capability as the firing frequency serves to maintian water in loose solution.. Plus, my mentor always said "send a man to do a boy's job" and John is doing just that with his filter arrangement..
George Morrison, STLE CLS

02-07-2003, 11:05
Called the top banana diesel service mechanic for Stanadyne
in our area who installs and services filter systems
into many of the agricultural rigs. I was just about to put this

Yikes! He says that they will *not* install a 2 micron primary filter
because of quick clogging of that filter and the resultant problems.
They have tried this before and he speaks with experience.
If I still planned to do the "pre-filtering" installation, he recommends
going with a 30 micron primary filter.

With the Duramax engine, he strongly suggests that any supplemental
fuel filtering be done as a secondary filter *after* the factory unit.
He also feels that with proper fuel lubrication, our factory filter set up
is fine.

OK, this reminds me of having a life threatening disease and then
consulting with 10 eminent medical experts. When you finished
asking all the questions........ you've got 10 different opinions

That's what is so great about this forum........ we keep learning.

02-07-2003, 12:50
"OK, this reminds me of having a life threatening disease and then consulting with 10 eminent medical experts. When you finished asking all the questions........ you've got 10 different opinions."

Well, in this case, not quite. Here we have 2 experts (JK & GM) and a bunch of enthusiastic amateurs.

02-07-2003, 17:44
We won't debate expert here but my filter has almost 700 miles on it and there is only a BB size drop of water in it. Time will tell on this. At least we have a bunch of different schools of thought testing ideas.

BTW- the Stanadyne tech I spoke to recommended my set up, I didn't actually take Todd's word for it although after speaking with him several times I think he is completely credible.

The reason I was asking for recommendations was to see if there was a better application for my purpose. The 2-mic was what was recommended for what I wanted to acheive and the tech seemed confidant the filter would go 6-7k miles which is the interval I intend to change it, along with the cc oil.

Also, the part numbers I got from Todd via e-mail aren't the parts I bought. My head had a different part number. Maybe something to do with the inlet/outlet size.

Sounds like the Stanadyne guys may not all be on the same sheet of music !?!

Final comment- if it clogs quick it must be filtering well! :D

02-07-2003, 20:33
While I might be a amateur I go by a old saying ,
"When you don't know something, surround yourself with people who do". Do you think Bill Gates is a expert programmer, no he has people do it for him.

As far as the 2 micron filter stopping up, that is installed pre-OEM. Mine is running fine, this filter has about 1200 miles on it so far. This no opinion, it is fact.

I have been looking for a good and inexpensive solution to our fuel filter problem. I have been working hard on getting good data. I assure any of you that anything that I put out about this subject is backed by scientific fact not just what I think. If the test results show that the Stanadyne won't do what it is supposed to do then I will be the first to admit it and then I will take it off my truck and find another.

Remember, I have nothing to gain with this. I am not sell ang anything, just giving free info. You can take it or leave.

Off my soap box now.

02-07-2003, 20:55

I am sure to be one of many that greatly appreciate the efforts you are putting forth on behalf of all.

There is no doubt more than on way to skin this cat.

The point is the deed must be done and you are one of several doing it.

Thanks again for all your effort and information.


02-07-2003, 21:11
Thanks and your welcome!!

Lone Eagle
02-07-2003, 22:14
John, I am no expert of fuel filtering but am very familar with hydraulic systems. The larger micron filter is always the first in series to stop the big stuff. We had several systems that uses 2 micron filters. Later! Lone Eagle

[ 02-07-2003: Message edited by: Lone Eagle ]</p>

02-07-2003, 22:27
My comment was not intended to offend anyone. After all, I'm among this group of enthusiastic amateurs. I meant only to point out that John and George are the people here who have the years of experience in this area, and the ones with professional reputations on the line. I, too, appreciate the efforts of srubrn, trace, and the rest. Peace.

02-07-2003, 22:27
Todd off his soapbox- me on mine.

As I said earlier, my fuel filter is working fine as well.

My GTech isn't telling me the truck is any faster or slower but the fuel mileage is getting better almost every week it seems. Now 5400 miles.

I drove 240 miles round trip today up I95 from Daytona north of Jacksonville and back, cruise set, trying to go 80 as often as traffic would allow and my on board computer said 18.4 avg. I have to love this.

My own calcs tell me the computa is pretty close.

I expect that when this filter begins to clog my boost gauge at WOT will fall off and my Gtech will also speak up and tell me hello.

Love the GTech too!!!

If and when this happens I will tell all.

Be it known there is no ego issue here. If I find a problem with my approach I will let you all know. As my yet un-met e-communication friend Todd has said, I sell nothing. I stand to gain nothing.

I spent +40g's for this truck. I will not let a $130, $330, or $530 fuel filter be a issue in my mind.

If JK's filter proves out to be the best solution I will give AMEX a ride on his train.

And for sure- I would not ever try to lead all of you down a rosey path into a pile of crap.

Thank you in advance for reading. tongue.gif tongue.gif tongue.gif

To the moderators-

I just love the way these little icons stick their tongues out and go yyyeeh... ??? you know!

[ 02-07-2003: Message edited by: TraceF ]</p>

02-08-2003, 00:11
I'm not going to get into this much more until I get samples from others that back mine up. The one common thing that I have seen with the exception of Greg L's and my samples is an INCREASE in the amount of dirt AND water post separator! :eek:

George sent me some interesting data from a PSD in which the OE setup did a very good job, but the addition of a Dahl system increased the particle count. He has also mentioned recalls on Stanadyne filter elements beyond the one reported by Sruburn (Todd).

BTW, the way that I have this set up, one could plumb either way. Pre or Post OEM. Moving on to engine oil bypass filtration...

[ 02-07-2003: Message edited by: kennedy ]</p>

02-08-2003, 06:44
I plan to get JK’s filter when its ready but I was also still thinking of installing the Dahl 100 (with heater) I already have (once it warms up around here that is). I bought the hose and fittings and was planning to mount it in the same position as Todd’s Stanadyne. The Dahl 100 has a 2-micron nominal (beta 50) cellulose filter and the de-pressureizer cone water separator that’s supposed to remove virtually all water (according to Baldwin). Since the DAHL is not as fine a filter as either the OEM or JK’s , and has a low-pressure drop (.75 inHg), seems like it wouldn’t hurt to have a little more margin. The DAHL is also a very good water separator and would provide some extra defense to a load of bad fuel with more water than the additive can handle. Is this overkill? Any thoughts? smile.gif

02-08-2003, 08:52
Don't understand the first paragraph in your last post JK. :confused:

This seems to say tests are done pre and post seperator and the element is making more water and dirt.

I am beginning to see some of the logic of a post oem filter although I still favor it being where I have it now. Having said that I acknowledge that these Stan filters we are discussing are widely used in all types of applications as a 'final' filter.

But- for my purpose, the 2-mic filter is the way I chose to go. The goal as I said earlier was ease of maintenence and clean and dry as possible fuel going into the oem systems, including the oem filter. The Stan rep's assurance that I would get decent life from the element was part of my decision.

This Stan filter is a breeze to change compared to the oem and if this has to be done roadside, the replacement element has a drain cock integrated. You don't even have to change the bowl until you are home and ready. We are talking 2 or 3 minutes tops. It doesn't install like the Racor or a typical spin on, it goes up and has a capture sleeve that twists a half turn and click locks. Pretty smart in my view and no tools needed.

I have been poking around under my truck trying to imagine where JK will put that assembly and as one poster already pointed out, there is a spot below and infront of the air box that may be able to accomodate it with some modifications.

Like the rest of you I can't wait to see it installed.

As a side note, after installing my Stanadyne, I left the oem in place about 300 miles, long enough to be sure I didn't have leaks at my flares, etc. I was prepared to fill the interruption in my fuel line with hose and clamps if necessary.

The Stan install went fine so at 5k miles I changed the oem. I have now cut it open and can send pictures to anyone who wants to see them. There was about 1/2 teaspoon of water in the bottom of it (I had never drained it) and no visual residue between the pleats.

I am establishing a baseline to measure the next oem replacement against and time will tell me what the Stan picks up and looks like under the same scrutiny.

More to come...


[ 02-08-2003: Message edited by: TraceF ]</p>

02-08-2003, 09:35
Trace F,

To summarize here:

Johnny C had a bacteria colony so he was counting dead bodies and is not a good test subject.

Sruburn had a defective filter element the first time, and now is looking to see if there may be room for improvement in his sampling technique as the correct filter also yielded a high count. Not sure about the water this time.

Another fellow did a Dahl system install and had a rise in particle count as well. He investigated and first found air (and dirt)leaks into his Dahl mount. Once these were fixed, counts came down a bit, but were still high. I believe the finger is now being pointed at internal leaks in the Dahl. This guy was SO thorough, that he removed and cleaned his tank prior to installing. He is an engineer for a MAJOR auto parts mfr.

I've also seen reference by George to Wix? filters releasing lots of particles when installed new. I guess what I'm trying to say is after seeing all this, I think that I am VERY fortunate to have gotten the results that I did on a freshly machined filter base!!!

02-08-2003, 09:57
Just a word of thanks to John, George, Todd, and Trace and everyone who's contributed to our knowledge for your hard work. I'm just one of the geese in the 'V' honking encouragement to the leaders here. I had to replace the fuel pump on my 97 6.5l TD at 80k and saw what that cost - and that was a relatively low pressure system. I'm very concerned about fuel quality and potential damage to my Dmax fuel system. I'm reading your posts with great anticipation and plan on going with the system that appears to do the best job for us.

Thanks from all of us who stand to benefit from the work of you pioneers. If you ever pass my way, there's a beer (well, OK, more than one) in the fridge in the heated garage for you.

Take Care - Don