Replace Duramax Fuel Filter

[Turbomax]

Hey y'all. I have an 04 LLY DMax. I continually have problems when I replace the fuel filter. First, I have arthritis in my hands & have difficulty changing the filter. Then, the primer on the filter housing has failed. The only way I can get it primed is to put air pressure in the fuel tank since it does not have a lift pump. I have an extra fuel filter housing from a 6.5 turbo. My question: Can I SUCCESSFULLY replace the DMax filter housing with the 6.5 housing & add an inline lift pump (similar to the 6.5) to assist in priming? BTW, I've replaced all the O rings in the DMax filter/primer housing 2 times. Still does not work. I think the little rubber flappers inside the housing may be at fault but neither rebuild kit had them. I would really like to use the 6.5 filter system since it is so much simpler & less painful to replace. Will this filter do a sufficient job on the DMax? Will it flow a sufficient amount of fuel? Will the elimination of the WIF sensor send any codes? I don't think the mounting bracket I will need to build will be difficult. Am I asking for problems? Please respond. Thanks!

[More Power]

The stock Duramax fuel filter is actually a better choice than that used by the 6.5.

With limited mobility or other disadvantages, you should consider removing the passenger side battery and/or the plastic wheel well liner to provide the best access to the fuel filter assembly. Acquire the aftermarket tools that make it easier. www.lubricationspecialist.com & www.kennedydiesel.com both sell spin-on filter wrenches and fuel filter replacement parts.

The plastic air bleed screw has been a problem for some. Machined aluminum versions are available.
Jim

[Turbomax]

Thanks Jim. As I said, I've replaced the O rings in my primer twice but it still doesn't work. I replaced the plastic bleed screw with a brass one. Do you know of a source for the little butterfly discs (or whatever they are called) inside the filter mount head? That is the only part I haven't replaced but neither kit had them. Also, do you think installing a lift pump inline (similar to the 6.5 setup) would help prime the system? I'm sure it would need to be powered all the time the truck is running???? Thanks again for your help.
Max

[Kennedy]

the butterfly discs serve limited to no purpose. If the system were "tight" they wouldn't be necessary.

Add a lift pump and solve your issue the right way while benefitting your fuel system at the same time.

[More Power]

As John mentioned, a lift pump can help - if it's designed for the Duramax.

Personally, I'd do what was necessary to get the factory Duramax fuel filter assembly to work correctly, then decide what if any mods might help in the future. I don't know what these assemblies go for over the counter at a GM dealership, but if the price is too high I'm pretty sure you could get one on eBay or through a national auto salvage company. New would be better but.... Maybe remove it, and take it to a fuel shop to have them fix it.

Jim

[Grayfox]

I saw a filter door that is installed into the fender liner. I think it might have been on the diesel
place website. Maybe someone can chime in on the door.

[DmaxMaverick]

The "filter door" is just a trap door installed onto the liner, allowing access to the filter area. Old idea. Not a bad idea, but more effort than it's really worth.

The liner is easy to remove, or just remove the rear fasteners and pull it down and out of the way. You can get creative with it, and install blind nuts or panel fasteners, and just remove the whole thing in less than a minute, at any time. Any of these are easier than installing the "filter door", and you don't have to cut the liner. You have the added bonus of access to the several other items behind the liner that will need attention, from time to time (glow plugs, intake plumbing, etc.).

[Kennedy]

Lube the push pins with either WD40 or better yet spray dielectric grease and they slide out like butter the next time.