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Fuel system won't prime

red

red

Being a lake bum in Texas
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Lake Brownwood, Texas
Changed the fuel filter on the duramax last weekend and can't get the fuel system to stay primed.

Last time I changed the filter I removed the air bleed screw, turned the ignition on to cycle the lift pump and after a few seconds all is well. Tried that this time with no luck.

Tried pumping the little pump on the top of the filter mount for 10 minutes, no joy.

Little bit of air pressure to the fuel tank and a few minutes later the fuel starts flowing to the filter. Fire the truck up and run out of fuel within a few seconds.

Thinking a dead lift pump, or am I missing something?
 
To my knowledge duramax doesn't have lift pump it's all in the injection pump, if it ran before filter change I'd go back to that remove try again did you miss something gasket?
 
Yep, what lift pump is on the truck? The ONLY DURAMAX to come with a factory lift pump was vans. ALL trucks did not, and still do not have one(cab and chassis's do have a transfer pump to move fuel from the rear tank to the front, but that's it). And also, you didn't put one of them plastic fuel filters on it did you?
 
It can be tricky to get the o-ring to seat all around the filter. The manual primer could need a rebuild too.
 
Swapped to a nicktane filter adapter and used a CAT filter, not a cheapo filter.

I'll remove the filter again when I get home and check it out. Could have sworn last time I turned the ignition and the system primed, might be thinking of the deuce and a half though lol.

I thought all the diesels had lift pumps?
 
No that one doesn't have a lift pump. The filter heads were known to crack and as I recall the primer was iffy at best on that specific truck. After checking the filter seals I suggest you order new seals for or replace the primer. I replaced the primer o rings once (aftermarket makes the O-Rings, GM doesn't) already so if you are in a hurry I suggest replacing the entire primer assy - not sold separately that I ever found. A lift pump added with an air leak can turn into a fuel leak.

I did return a plastic Wix fuel filter after it sucked air at the WIF sensor and nearly stranded me.
 
I used new seals with the adapter.

If the stock base/primer is iffy at best, anything wrong with upgrading to a lift pump and a better filter base? Want to run a 2 stage filter setup anyways
 
Well, discovered the problem. Pulled the filter and adapter off to compare them. Good seals. On the old filter there is a cross piece in the suction side of the filter, pushes the ball valve open to allow fuel to flow from the filter to the pump. My adapter has nothing there to open the ball valve.

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Glad you found the problem.

That valve prevents fuel from dripping all over everything from the line going to the CP3. Fuel flows from the outer holes to the center of the filter. the entire filter is on the suction side but the center is the clean side going to the CP3. The check valves in the primer prevent fuel from going back to the tank.

The filter head has a fuel heater in it. Other than that you can replace it completely with something better.
 
That check ball is opened via vacuum when the engine is running. Nothing is meant to push it open. Also it says in the nicktane directions to remove the check ball when you install the nicktane adapter, so it shouldn't be in there with the adapter anyways.
 
Good deal. Just so you know. .. I'm still running the standard fuel system setup. I do have a set of shims to install in the FPR but haven't gotten to it. Truck still runs excellent as currently set up
 
^^^^

I get the Racor (OEM) filters from Greg (Lubrication Specialist) and replace them yearly, right around the 15k mark. I had no issues with the Wix plastic filters, but after hearing issues with them, I'll stick to the OEM. I just replaced what appeared to be the OEM (120k miles) fuel filter on the 08 GMC C4500 we bought this spring, so I'm glad I try to keep up on maintenance. That was kind of a PITA to replace...
 
I run CAT filters on both my trucks, makes it easier for me.

The truck runs great with the tune, little more smoke at wot than I want. Planning on an exhaust upgrade next.
 
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