hey guys i have a buddy who has a 97 12v and he recently replaced the fuel lines from tank to lift pump and the return line. he thought that he corrected his problem of sucking air into system.but you still have to pump the hand primer before u starte it and it cranks a while. he told me that he disrupted the 2 steel pipes coming out of the top of fuel tank and he put some JB weld on it.i belive that he is suckin air from where the 2 pipes come out of tank?

 

It's possible he's sucking air there or somewhere else, if it's the supply line that's leaking. If it's just an air leak into the fuel tank, it won't be the problem, not that it doesn't still need to be addressed.

If he can pressurize the fuel tank slightly, and carefully, with compressed air, it should cause wetness to appear at any air leak to help him find it. It is also handy to have a pressure gauge to tap into the system, so the lift pump and overflow valve can be tested.

 

Those connections on the top of the tank can break quite easily, especially when rusty. Unfortunately, he might need to drop the tank and replace the pickup tube.

If that isn't the problem, the other likely suspects are the fuel heater and having an extra gasket on the fuel filter(a lot of people forget to take off the old one and it won't seal with 2 gaskets).

 

A known failure is a hole rubbed in the coiled pickup tubing inside the in-tank module.

If there's nothing big in the bed (camper. etc.) and a hoist or several buddies are available, it may be easier to pull the bed than drop the tank.
Just a thought.

 

Dropping the tank takes all of 20 minutes, pull your electrical connection, make sure the fuel lines have enough slack, un-clamp the filler neck, and pull the strap bolts. I had the same problem your buddy is having. I wasn't willing to drop over 400 coin on the pickup, so I took some urethane paint and painted the two elbows coming out of the tank a few times, it sealed them right up. If he doesn't like that idea, there is a vent line on most of them (its plastic and will have a cover on it) that he can se as a fuel pickup, but there is no screen on the bottom of it, so if a chunk of something gets suckked up into it he's toast.

 

thanks for the input guys.the truck is a 1ton dump so it was queit easy sure enough the suckshin pipe comming out of module had a couple of pinn holes in it. how much does one of those things go for $$$ ?

 

Too much from Chrysler, that's a given. Salvage?
How about some JB Weld?

The extra suction port capped off with a rubber cap is the "auxiliary" fuel pickup, intended for a welder or such. As well as not going inside the "screened" area, it also doesn't go as close to the bottom of the tank. That way, if you're sitting out on a site welding all day, you can't completely run your truck out of fuel.

If you don't like the JB Weld idea, you could possibly fabricate a custom pickup tube with a piece of tubing, a compression fitting, and some washers.