Fuel Filter Test Results

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.

Todd
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.
Greg

Choreboy,

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.


WOW!

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 !"

Questions:

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

Steve,

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?

SWLA,

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>

SWLA,
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.

SoCalDMax,
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?

At the risk of opening another can of worms:

www.preporator.com


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...

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.

LA DMAX

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..

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.

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.

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.

Kerry

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…?

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.

Greg

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.

Mike

Greg, What do think is the best way to tap in to the fuel line?

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.

Greg,

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.

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.

Todd
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.
Greg

Greg,
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?