Well at first i could not find any fuel leakage, if i park my truck with the front level or up hill, it losses its prime and is a pain to start after many hours. I am lazy so just started parking with the front of the truck pointed down hill so it doesnt lose its prime. Recently i discovered that there seems to be a small fuel leak coming from the lift pump/filter area, that runs down the block. I assume this is why i am lossing my prime every night. My question is i cant see down/up in there well so what are the possiblities of the leak, is it mostlikly the lift pump or somthing else. It doesnt appear to be the filter or pre heater leaking but will go over the area when the weather is nicer and i can get out to look at it.

i have experienced the same problems with 1/4 and a full tank of fuel, so thats not it.

any help is appreciated, thanks, matt

 

return line runs right in behind there, that could be it. Easiest thing to do would be to pressurize your tank and watch for the leak to show. Could be the lift pump too, or the drain on the filter. . . just takes a couple PSI and a helper.

 

alright ill check everything out and see what i can see.

thanks

 

I'm fighting this on my brother-in-law's truck right now. He replaced the lift pump thinking it was the cause, but, the problem still persists. They pressurized the tank and didn't see anything leaking, but, I don't think they looked well enough. Today, I found out they replaced the lift pump and was told it didn't fix the problem. When I looked, I found diesel dripping off the lift pump and traced it back to the drain on the fuel filter above it. It appears to be seeping out from around the plunger shaft of the drain. When I pulled the filter, it was maybe about 1/4 full. He thinks a piece of dirt got caught somehow and was allowing it to leak, so, he cleaned it. We didn't have any extra diesel to fill the filter up and I ran out of time, so, I'll have to let you know it cleaning the drain plunger worked or if he'll have to get a new one. Anyways, check around the plunger part of the filter drain for diesel. I wasn't there when they pressurized it and find it hard to believe it wouldn't have showed a leak there under pressure, but, in their defence, it is a bit tough to get a good line of sight at that plunger, especially if they were frustrated.

 

Thanks, Hercules. I havent got a chance to go out and look over everything yet. Ill give the drain on the filter an extra look over when i make it under there. If it looks like that where my leak is coming from i might just by a new filter drain assembly on acount that the plunger is broken off from mine. I would like to just fine a plug i could put in the bottom of the filter since i never touch the drain and change my filter quite often.

I found the replacment drain/plunger assembly, but does anyone know what will work or where i can find a plug to fill up the drain whole on the bottom of these filters?

 

My brother-in-law mentioned the same thing about taking the filter with him to match to a pipe plug of some sorts. I'd rather see him just get a new plunger assembly, especially since it would be less than $35 to replace it. The plunger assembly is actually called the fuel water sensor, if I remember correctly and in case your wondering. It just does double duty as the filter drain.

Don't forget to check the fuel line that runs behind the filter. They are notorious for dry-rotting and leaking as a result.

 

You need to check your fuel heater. It is very common that a leak will be at the connector for the fuel heater. The heater is not necessary so you can remove it. Simply unplug it and screw the bowl off the bottom and then use an allen wrench to remove the bolt retaining the heater element. Then clean the strainer and screw it back on the bracket without the heater. Be sure the oring is in place on the bowl and you removed the heater oring.

 

what Guru said, I think the allen head is 8 mm, I bet your filter screen is somewhat clogged

 

I just got in from working on my brother-in-laws truck and, Guru beat me to the solution, the problem was the fuel heater. I realized the problem had to be between the filter and the tank. The lines flowed fuel, there was a new lift pump already installed, but, if I pumped the primer button without the filter on I barely got any fuel. I ended up completely bypassing the fuel heater housing. My brother-in-law didn't want anything to do with just removing the heater portion, so, I used a fitting with 1/2" pipe thread on one side and 1/4" nurled on the other. I think it was 1/4", I just happened to have a fitting that worked. I removed the existing 90 deg fitting on the end of the lift pump that connects the lift pump to the fuel heater via a little rubber hose and replaced it with the 1/2" pipe fitting mentioned earlier. I then removed the rubber fuel line from the metal line that feeds the fuel heater and attached it to the fitting I installed in the end of the lift pump. Completely bypassed the heater housing and no longer have fuel problems. I don't know why he wanted to completely bypass the heater housing, but, it's his truck.