On Sunday I replaced my transfer pump with a new one from Cummins. It's important to note the the old one was working fine, it was weeping out of the manual button, but the truck ran great. Anyway, out of preventative maintanence I replaced the transfer pump. I got the truck started and it drove weak and after sitting two hours it had lost it's prime. I pushed on the primer button and heard air escaping out the fitting on top of the pre-filter bowl. I tightened up the brass fitting until I didn't hear any more gas escaping. I re-started the truck and took it for a test drive. It died about an 1/8" mile from my house. It had sucked all the fuel out of the fuel filter canister. I re-filled the filter canister and started the truck again. I let it idle for about two minutes before it died. Again, it had sucked all the fuel out of filter canister. I took the new pump off and replaced it with the old pump. Other than the weeping primer button, it was working fine before I changed it. Now it does the same thing. the truck will run for about two minutes and dies. it draws all the fuel out of the fuel canister. If I don't get it fixed tonight I will have to take it to the dealer tomorrow. (Cummins is backed up for four days)

 

Forgot the most important part. It's a 1997 Dodge with the 12 valve Cummins.

 

I think that you must have a loose fitting, or perhaps you disturbed the rubber lines and one of them cracked.
Guessing

 

The info at the bottom is for a 2004 so I'm not sure if it applies exactly to your year model. However, I'd be willing to bet that your lift pump should run for approx. 2 seconds after turning the ignition switch to "on" (but not start). Lift pump should also run for 25 seconds after "bumping" the starter (but not actually starting the engine). Try "bumping" the starter several times to prime the lift pump before actually starting the engine. If you don't hear the lift pump running when trying to prime then you must have an electrical problem somewhere (fuse?).




The transfer pump is self-priming: When the key is
first turned on (without cranking engine), the pump
will operate for approximately 2 seconds and then
shut off. The pump will also operate for up to 25 seconds
after the starter is engaged, and then disengaged
and the engine is not running. The pump
shuts off immediately if the key is on and the engine
stops running.

 

Like mentioned, the fuel system is probably sucking air somewhere. Check the metal lines that you removed as well as all of the washer/seals. I agree with smokee, the rubber hoses are suspect as well.

Another thought, is the pump rod that rides along the cam in the correct spot? Not sure if it matters, not sure if there is a right or a wrong way to put it in, but I hope someone with more knowledge than I will help you out. I can check my Haynes and see what it has to say, will get back with you this eve.

Handymantim, the lift pump on the 12 valve motors is like the old style mechanical fuel pumps on a car. So nothing electrical happens with the lift pump whan the key is turned on. Good luck, Kevin

 

I remeber reading something about bad rubber fuel lines but for the life of me I can't remember what years the trucks were that had this problem.

But I do agree 100 % that your sucking air instead of fuel .


Jason