Replace fuel filter now no start

Our '02 2500HD started surging a bit at idle, and taking just a bit more time to start. Nothing bad, but it's one of those 'hmm, that took two more turns of the crank than usual' sort of thing. Based on searches here, the place to start was a new fuel filter. It had been a while, so I figured why not? Got the filter, WIF eliminator kit and aluminum bleeder cap from KD, and finally got time to work on it. What a PITA. I now remember why I don't like doing these things! I seem to remember going in over the fender with the last change. This time, I had to pull the inner fender liner, as I was just about to drive a screwdriver into the filter just as my wife managed to pop it loose.

New filter on, and started pumping the primer. I probably pumped the thing 10+ minutes, in 95-degree heat, I might add. Never saw fuel in the bleeder hole. I had my wife turn the key on a couple of times, to see if we could get some help from the pump, but nothing. After another 5, or so minutes of pumping, I had her start the truck. Started, ran for 15 seconds, then died. Opened the bleeder screw and still no fuel. I then remembered that the WIF eliminator had a drain on it. Opened it and... nothing. I'm not getting ANY fuel in the filter. Reading other similar posts, I removed the fuel cap to make sure no vacuum. Nothing, no sound of sucking air, or anything. With the cap off, I tried pumping again to no avail.

What's next? I'm at a loss for a solution, other than dropping the tank and checking the fuel pump.

Unless you added one, it has NO fuel lift pump, in the tank or elsewhere. The primer pump you were pumping is it until it's running (the high pressure pump draws fuel, all the way from the tank, but will not self-prime).

It can take 100-200+ primer pump strokes to get fuel after a filter change, and can be worse if the truck is parked nose-uphill (more fuel drains back to the tank), or if it takes a long time during the filter R/R.

The hand primer pump draws fuel. It isn't positive, and must be able to draw air until fuel is present. They can fail, and not pump at all, but they usually leak and cause other issues long before that. Repair kits are available.

It sounds like the filter canister isn't sealed. Most often, the large top O-ring gets out of place during installation, which prevents vacuum, and the ability to draw fuel, either with the hand pump or high pressure pump. You'll have to R/R it again, making sure the seal is fully engaged. Other possibilities are, the WIF eliminator isn't sealed, or the center seal is either missing, or the old one wasn't removed (now with 2 of them stacked). Look at the old filter and make sure BOTH top seals came out with the old filter, and the WIF sensor O-ring is in place, tight, and the drain is sealed. When I replace the filter, I pack the large O-ring groove with grease and push the O-ring into it. The grease keeps it in place.

Another possibility is a cracked fuel filter assy. Some can be repaired (J-B Weld), and some can't, due to the crack location and severity. Replacement assemblies are available, OEM and aftermarket. If you use aftermarket, make sure it has a primer pump, or add an electric lift pump that can be used for priming. Remember, the engine-driven high pressure pump will not prime itself.

If you are sure everything is sealed up and still not getting it to prime, you can use low-pressure shop air at the fuel filler to push fuel up to the filter. Remove the bleed screw and add air pressure to the tank (about 5 PSI) until fuel is at the bleeder. Close the bleed screw and pump. It should be able to prime high pressure pump, now. Add a primer pump repair kit to your short list.

Thank you. Truck is sitting perfectly level. It o-ring for the filter was a bit dodgy, but it looked sealed all the way around. I'll get a light and mirror on it in the morning. The old o-ring is with the old filter. I cleaned the mounting surface after pulling the old filter off, to wipe off any oxidation.

I used oil for the o-ring, and watched as the filter was lifted into place to make sure it wasn't disturbed, although it was a real PITA to get the filter to start threading onto the housing. I did watch the mounting surface of the filter as it got spun onto the housing to make sure the o-ring wasn't sitting up, or out of place.

I didn't have this much trouble with the last filter change.

First, is this a plastic canister filter? If so, I highly recommend replacing it with the metal filter. Lots of issues with the plastics, sooner or later.

If it was REALLY hard to start threading, suspect the old inner seal (grommet) may still be on the nipple. When removing the old filter, the seal will sometimes stick onto the nipple. It should remain with the old filter, but they often don't. The filter will spin on with both in place (with difficult threading), but will make it difficult for the outer O-ring to get full engagement and seal.

Not really hard, it was just awkward, and I have a bad shoulder, so installing the filter was a one-hand operation, which I couldn't push up and turn at the same time. My wife had to do that job. Once it threaded, it was a breeze to tighten. It's the Baldwin spin on filter that Kennedy Diesel sells.

Back to basics, then. Either it isn't sealed (for whatever reason), or the primer pump isn't moving air/fuel. Not discounting other possibilities, the most common issue, by far, is an improperly sealed filter canister.

I plan to remove and reinstall the filter today. Thanks.

This thing is kicking my butt! After several off and on episodes, I replaced the filter with a WIX and reinstalled the WIF. I figured I'd see if just throwing more parts at it would help. Still could not fill the filter with the priming pump. I could press the plunger down, cover the bleeder hole with my finger, let off, and could feel the vacuum when pulling my finger off the hole.

Using a vacuum tester, I pulled a vacuum on the filter assembly until I got fuel in the filter (actually got fuel in the tester, but it was VERY old and beat up anyway, I needed to replace it). With that, I could press the priming pump and get fuel in the bleeder hole. So, I capped off the bleeder hole and pumped, and pumped, and pumped. I remember counting at least 500 pumps with the bleeder cap on and the pumping never got hard.

Frustrated, we tried to start the truck. Nope! So, I started looking for a fuel pump. The FSM says it's mounted on the frame rail, but where? I crawled under the truck, and looked around and there's nothing between the fuel cooler and the engine, but the ABS pump. WTF is the thing? Did GM STILL make a frame-mounted pump that you have to drop the fuel tank to get to?!? Shame on GM if they did.

I'm seeing nothing in the FSM regarding dropping the fuel tank to R&R the pump, so do not know for certain. Where is the thing, and should I at least hear it spin up with KO if I'm under the truck?!? Thanks.

It DOES NOT have an OEM fuel lift pump, electric or otherwise. Some later model van and chassis models have one for priming only, but your LB7 truck does not. Previous 6.5L Diesels had one on the frame rail below the driver's seat. Your FSM is either not for your model and year, or is only suitable for privy duty.

It sounds like your primer pump has quit. Repair kits are inexpensive and easy to install. A failed pump can also allow air to leak in, causing the high pressure pump to lose prime.

Once you get the truck primed and running, it will stay that way until enough air leaks in to lose prime. If you can't wait for the primer repair, try using low pressure shop air (~5 PSI) at the fuel filler to push fuel to the HP pump, while someone cranks it. Don't crank more than about 20 seconds before allowing the starter to cool for a few minutes. Once it starts, let it run long enough to clear out any remaining air. As long as you don't open the filter assy to air, it will continue to start and run. If it loses prime again (before repairing the primer pump), suspect an air leak, probably the primer pump.

HUH. 2002 Service Manual Silverado/Sierra, page 6-3191 shows a frame-mounted fuel pump fr the 6.6. This FSM seems to be pretty content-free for usable information, though, so I guess it's possible. With the fuel filter full, I'll try the pressurize the tank and crank method.

This thing has been 100% trouble free until now.

Primer pump rebuild kit has been ordered.

Were you able to start it, and keep it running? The reason I ask is, if the filter assy has a crack, or is otherwise unable to maintain a vacuum (poor line connection or other damage), the primer condition won't matter. If it loses prime due to the primer, it can be sealed once the engine runs, to eliminate or confirm it. There are simply too many possibilities.

I would think pressure in the fuel tank would disclose any fuel leaks.

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Originally Posted by a5150nut

I would think pressure in the fuel tank would disclose any fuel leaks.

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Probably, maybe. Leaks aren't always 2-way and, depending on the leak, can suck air in and not leak fuel out. A failed primer pump will often show a bit of fuel leakage, but not every time, or immediately.

I haven't gotten it started yet. I figured I'd just go ahead and R&R the primer pump, in hopes that I can use it to get the system primed properly. Note that I'm seeing no evidence of any cracks on the filter housing, nor is there any seepage anywhere on it. While depressing the primer pump, I can put a finger on the bleeder hole and feel/hear vacuum when releasing the pump. I would assume that's an indication that the primer is working, but I guess there could be some bypass on the downstroke preventing fuel from being moved downstream of the primer pump. That's just a guess, though.

When I have had to prime mine I leave the bleed screw closed while pumping. Once pump starts to get firm I crack the screw and release the air till I get fuel squirting out.

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Originally Posted by a5150nut

When I have had to prime mine I leave the bleed screw closed while pumping. Once pump starts to get firm I crack the screw and release the air till I get fuel squirting out.

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Normally, that's how it should work. But, that assumes something isn't broken. OP said continued pumping didn't bring up fuel, but he could when using a hand vacuum pump (essentially the same as using the primer pump), then couldn't get the primer pump to push fuel to the HP pump. Something is broken, and I hope it's as simple as the primer pump. It could certainly be something else, but the pump is the most simple and least expensive starting point.

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Originally Posted by a5150nut

When I have had to prime mine I leave the bleed screw closed while pumping. Once pump starts to get firm I crack the screw and release the air till I get fuel squirting out.

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And that's how it worked the last time I did it. Fingers crossed it's just a dead seal in the priming pump. Luckily, it looks like filter assemblies are still available new. Hoping I don't have to go that route.

Now waiting for the priming pump rebuild kit to arrive.... and my hand to heal some from all the pumping I did to get the thing to prime. 1000-or so pumps, and the hand got tender to the touch.

Gene I thought you said you were pumping with screw open. My mmistake.

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Originally Posted by a5150nut

Gene I thought you said you were pumping with screw open. My mmistake.

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Heh, desperate times call for desperate measures. I tried both. Nothing worked, except pulling a vaccuum on the assembly via the bleeder screw.

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Originally Posted by gbeaird

Nothing worked, except pulling a vaccuum on the assembly via the bleeder screw.

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I think that eliminates a leak on the suction side as a possible cause, which leaves the primer pump as the most likely suspect.

Installed the rebuild kit. The pump seals were hard and worn, so they were suspect. After putting everything back together, however, we're still not getting it to start. I DID just do the top end of the rebuild kit, but since I'd have to pull the assembly off to do the o-rings on the underside, I've just gone ahead and ordered a new filter housing. I should be able to pick it up Tuesday at my local parts house. It'll probably be in my hands before the NAPA rebuild kit ships (which hasn't happened YET!).

We tried pumping it a couple of hundred times, with no luck. Tried gently-pressurizing the tank and cranking the engine over. Tried gently-pressurizing the tank and pumping the priming pump, and, again, still nothing.

Still digging our new Honeywell portable A/C out in the shop, though!! :-)

When you R/R the old hose connections, make sure the clamps are reinstalled exactly as they came off. The clamps will have embossed the hose, and if not reinstalled exactly as before, they will likely leak.

Than you. Yes. And I do plan to reuse those spring-style clamps. Any 'secrets' for getting the old hoses off the metal lines? I'm sure they've annealed themselves to the metal by now.

No secrets. Just don't try to pry under the hose unless you plan on replacing it (damages the sealing surfaces). If they're fused to the nipples, try to rotate the hose a little, and wiggle it back and forth while pulling away. If they won't budge with only hand pressure, I use a slip-joint plier or channel lock to gently persuade them. If that doesn't work, it generally requires replacement. Sometimes, you can get away with shortening and/or splicing them. The OEM hoses are formed, so bulk hose can present problems, either by being oddball size, or not liking to bend enough (kinks). Barbed couplers and alternate pieces of hose can be used, if it comes to that, while the OEM hose is on order. Pressure and temperature isn't extreme, so fuel compatibility and a good seal is all that's really needed.

Yeah, wanted to avoid slip-joint pliers, as they'll cut into the old hoses, even with the lightest of pressure, it seems. I don't think there's enough 'excess' hose to cut and reuse. GM isn't known for being generous in any way.

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Originally Posted by gbeaird

HUH. 2002 Service Manual Silverado/Sierra, page 6-3191 shows a frame-mounted fuel pump fr the 6.6. This FSM seems to be pretty content-free for usable information, though, so I guess it's possible. With the fuel filter full, I'll try the pressurize the tank and crank method.

This thing has been 100% trouble free until now.

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The chassis cabs and other commercial builds for these trucks had 2 tanks... A "lift" pump (or more rightly named transfer pump) was used in those applications, to move fuel from the aux tank to the main tank. In those commercial applications, the transfer pump doesn't move fuel from the tank to the engine. Pickup trucks, on the other hand, were never given a fuel lift/transfer pump at the factory because they only have one fuel tank. The service manuals include the fuel pump electrical diagrams and service data for them because a mechanic could encounter one. It would have been nice if the manuals stated which trucks would have an electric fuel transfer pump - to avoid confusion.

I changed the fuel filter on two separate Duramax pickup trucks last year. The pumping plunger on each truck primed the fuel system relatively fast.

One tip I recommend is to loosen the fuel tank cap while changing/priming the fuel filter. This helps to prevent either pressure or vacuum inside the tank from affecting the process. Pressure could cause a spill problem when the filter is removed, or a vacuum problem could fill the entire fuel supply line system with air when the filter is off. Each problem makes changing a filter harder.

Good luck, and let us know what solved your problem. Jim

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Originally Posted by More Power

The chassis cabs and other commercial builds for these trucks had 2 tanks... A "lift" pump (or more rightly named transfer pump) was used in those applications, to move fuel from the aux tank to the main tank. In those commercial applications, the transfer pump doesn't move fuel from the tank to the engine. Pickup trucks, on the other hand, were never given a fuel lift/transfer pump at the factory because they only have one fuel tank. The service manuals include the fuel pump electrical diagrams and service data for them because a mechanic could encounter one. It would have been nice if the manuals stated which trucks would have an electric fuel transfer pump - to avoid confusion.

I changed the fuel filter on two separate Duramax pickup trucks last year. The pumping plunger on each truck primed the fuel system relatively fast.

One tip I recommend is to loosen the fuel tank cap while changing/priming the fuel filter. This helps to prevent either pressure or vacuum inside the tank from affecting the process. Pressure could cause a spill problem when the filter is removed, or a vacuum problem could fill the entire fuel supply line system with air when the filter is off. Each problem makes changing a filter harder.

Good luck, and let us know what solved your problem. Jim

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Thanks for the description, Jim. Funny, the FSM doesn't mention that it's a 'transfer' or 'aux' pump, just that it's a pump. All priming attempts post the first day have been with the gas cap off. We have drain buckets under the filter housing when swapping them out, and even open the WIF draw a bit to make sure at least some of the fuel drains from the filter to hopefully minimize spillage.

Success!!!!!

Got the new filter housing, Baldwin filter, aluminum bleeder screw and WIF Plug installed on our truck. With my bum shoulder, my bride was very instrumental in getting this accomplished. As Jim mentioned, it primed very fast, once all the parts are working as expected! On the third pump, I knew things were different, and hoping that was a good difference. It was. I bled the system 3X, with the 3rd time bubbling mostly fuel. Had my trusty assistant try to start the truck, and on the third spin, it fired right up, and idled perfectly smooth. ZERO perceived surge at idle.

The A/C is still leaking down, though. I was hoping it was just the leaking cycling switch, but it seems that's a no. Now guessing the schrader valves need replacing. Sigh. That'll be next, but for now, just happy we have a running truck. We can how go to our next autocross event!!

When I was pulling the passenger-side inner fender liner, the following bit dropped out at the back of the wheel well. Any idea what it is? I'm guessing it's some sort of cab ventilation flap, to prevent the cab from pressurizing, but don't know for sure. I guess I can dig through the FSM, but right now, I need to go wash diesel off of me.

Attachment 6587Attachment 6588

Thanks, all, for the help and patience with me as we worked through this experience. This has been a great truck, except for this one thing. Hopefully, we can go many more years before that filter has to be replaced again.

Did you see Robins post on her schrader valve tool?

I don't get over to this part of the interwebs that often, so no, I didn't. Do you mean this post:

https://www.thedieselpageforums.com/...der+valve+tool

? Looks like it could be a cool tool, but not certain how to make that work with the QD fitting on the respective ports on the truck. Nice to know that kind of tool exists, though, should I need it for the home condensing unit. I'll probably just pull off as much freon as I can, R&R the valve and then vacuum and recharge the system.

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Originally Posted by gbeaird

I don't get over to this part of the interwebs that often, so no, I didn't. Do you mean this post:

https://www.thedieselpageforums.com/...der+valve+tool

? Looks like it could be a cool tool, but not certain how to make that work with the QD fitting on the respective ports on the truck. Nice to know that kind of tool exists, though, should I need it for the home condensing unit. I'll probably just pull off as much freon as I can, R&R the valve and then vacuum and recharge the system.

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"Schrader" valve is only a description of a type of QD (Quick Connect/Disconnect) fitting. They are many different sizes and configurations, but all work about the same. A schrader valve tool for your home HVAC would work essentially the same as one for your vehicle(s). Schrader valves for refrigeration systems are almost always the same, respective of the refrigerant used in the system. The tool Robyn has/used allows the replacement of a valve core with minimal loss of refrigerant. If your system has leaked all the way down, then a vac/fill may be the best option. If it's only leaked enough to cause pressure switch cycling, then using a valve tool for a leaking schrader valve may be the best option. HVAC servicing has become increasingly more costly, and any DIY solution is almost always a fraction of a professional service price tag.

It's great to hear you're up and running otherwise.

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Originally Posted by DmaxMaverick

"Schrader" valve is only a description of a type of QD (Quick Connect/Disconnect) fitting. They are many different sizes and configurations, but all work about the same. A schrader valve tool for your home HVAC would work essentially the same as one for your vehicle(s). Schrader valves for refrigeration systems are almost always the same, respective of the refrigerant used in the system. The tool Robyn has/used allows the replacement of a valve core with minimal loss of refrigerant. If your system has leaked all the way down, then a vac/fill may be the best option. If it's only leaked enough to cause pressure switch cycling, then using a valve tool for a leaking schrader valve may be the best option. HVAC servicing has become increasingly more costly, and any DIY solution is almost always a fraction of a professional service price tag.

It's great to hear you're up and running otherwise.

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Yes, I know that. I've spent some time in residential HVAC work, in a previous life, and maintain our vehicles' systems myself. I'd have to have a closer look, but IIRC, the charging ports require a QD connector, and there is no way to thread the end of the tool on the port. I don't know if there's a QD connector that has a metal adapter to thread to the tool. All I have seen for automotive use are flexible ends that connect the servicing lines to the charging ports on the vehicle. Again, I'd have to do some searching.

The first one in a search:

https://www.amazon.com/dp/B085VGN791

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Originally Posted by DmaxMaverick

The first one in a search:

https://www.amazon.com/dp/B085VGN791

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Ahh, I saw no links in her post, but this is VERY helpful. Ordered! Thank you!!

Got the race car to, and from the event today with zero issues from the truck! Car got hot again, so we packed it in early. Ran out of time to test the schrader valve replacement tool, maybe this next weekend. Thanks, all!

Thanks for the update. I'm looking forward to your experience with the tool. I don't have one, but may need one soon.

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Originally Posted by DmaxMaverick

Thanks for the update. I'm looking forward to your experience with the tool. I don't have one, but may need one soon.

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Will do. Yeah I get a puff of pressure when I pull the low-side cap off. I think the high side port is leaking on our 95 SS.

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Originally Posted by gbeaird

Success!!!!!

Got the new filter housing, Baldwin filter, aluminum bleeder screw and WIF Plug installed on our truck...

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Good job!

About 4 years ago or thereabouts, I visited a local diesel shop for some service I didn't want to do... They recommended that they rebuild my truck's original fuel filter housing due to problems with the pumping plunger mechanism in a certain percentage of other trucks they've serviced. It was pretty cheap, so I said "Go ahead". Might be a good thing to do for most of us... Jim

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Originally Posted by DmaxMaverick

Thanks for the update. I'm looking forward to your experience with the tool. I don't have one, but may need one soon.

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Originally Posted by DmaxMaverick

Thanks for the update. I'm looking forward to your experience with the tool. I don't have one, but may need one soon.

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FINALLY, an update! Been a while, I know, but we have many, many other projects in the shop. The tools are 'okay'. While they look nice, they're kind of mid-pack in the 'precision' department. In fact, I discovered the locking ring for the valve remover tool was malformed and came off when I was applying refrigerant oil to the mechanisms. Luckily, that part of the high and low side are the same, so I just used the other one.

It takes some 'fiddling' to get the schrader removal tool down on top of the schrader valve. Once locked in, it does pull the valve back up into the back chamber for R&R. The SS, is seems didn't have any pressure remaining, but I still used the tool. The truck was still pressurized, so when I got the valve loose enough to allow refrigerant to escape, it popped the tool up with the pressure. Unfortunately, it didn't take the valve with it, so I had to go back in, grab it, and continue to use pressure on the tool to 'spin' the valve up and out so it came up with the tool. Once I did that, the operation worked, as-expected.

My back was starting to spasm, as I'd been spending most of the day half-way bent over car fenders on other projects, so didn't get the high-side valve replaced. Maybe tomorrow, since we're off.

I'd probably still get this tool, as it does seem to have some utility, but it is 'fidgety' at best. I used the schrader valves that came with the tool. I probably need to get some better valves, but I'm kind of guessing they all pretty much come from the same factory in Shengen, anyway.