Duramax won't prime.

[Beaker]

2008 Duramax
Went to start truck, took a second or two longer than usual and only ran for a couple of seconds. Will not prime. Fuel filter changed about 2 months ago but only about 100 miles since then.
Coincidence?

[Beaker]

Thanks for all the replies and thoughts. I gave up working on vehicles years ago but did drop fender well to tighten fuel filter.
Moved very little and with a mirror to see back of filter, the o ring did not seem to be protruding. Was towed to shop where owner says probably will be end of week to get to it. Said as the trucks get on in years that they can develop pinprick holes which of course destroys vacuum. Possibility of installing electric pump. Will find out by end of week.
Thanks again.

[Huntindog]

deltabravo wrote:
x3 on filter head rebuild, or the o-ring on the filter isn't seated in the channel.

I've had issues with that o-ring staying in place too.

Video on the fuel filter change

coating it with vaseline helps keep it in place.

[deltabravo]

x3 on filter head rebuild, or the o-ring on the filter isn't seated in the channel.

I've had issues with that o-ring staying in place too.

Video on the fuel filter change

[bucky]

The link is correctly to the fuel filter housing.

[Lantley]

If you do a little research you will find the filter housing is a well known issue. There are various rebuild kits to replace the "O" rings and seals or you can just buy the entire housing.
I replaced the entire Assembly in my O7 dually at about 250K.



Duramax oil filter Housing

[Grit_dog]

What Davis envy said. Forgot. O ring is replaceable.

[edatlanta]

The fuel filter o ring is very easy to not have seated properly when installing. Are you sure your o ring is properly in it's channel? If not it will cause an air leak. The Duramax system is a vacuum system and not pressurized, so you could just have an air leak.

[davisenvy]

There's an o ring under the primer bulb that goes bad. It won't allow you to prime your fuel and won't let your truck to start. The o ring is $10 at your local auto parts store. Good luck.

[Grit_dog]

Primer is known to suck air. Like the videos posted.
One way to prime it without Using the primer Is to pressurize the fuel tank, slightly.
Seal up an air hose to the tank at like 5-10psi. It will prime the system and truck will start. If it doesn’t hold then either the primer or bleeder is sucking air likely.

[Chinolbz]

x2 on the filter head failure.

[Beaker]

motofell1 wrote:
You could check by releasing the bleeder screw and pumping like you're priming a new filter - if fuel squirts out right away you know you have fuel that far

Yes, that what I mean won't prime, cannot get fuel to squirt out.
Ran fine when I shut it off a week ago.

[killerbee]

If this happened within an hour of shutting down the motor on a hot day, it is a prime issue. Specifically it is diesel vapor forming in the hot filter and line. Just continue to pump, then try to start. Repeat until all the bubbles are out. This will be easier if you leave the hood up for an hour or 2, but can be done when hot.

[Turtle_n_Peeps]

I'd bet $5 that this is your problem.

Easy fix and pretty cheap.

[SweetLou]

I once had an '87 Ford 6.9 and when I had priming issues, I put an electric fuel pump on it so I didn't have to crank the motor. Got fuel to the pump and off we went.