Engine/Transmission (1994 - 1998) Best source for a new lift pump?

[PRattenbury]

Hi, it appears my lift pump needs to be replaced. It's only putting out about 4PSI. Where might the best place be to purchase a new one?? Thanks for your help!

 

[bmoeller]

Before you replace the pump, I would replace the overflow valve. That is what controls the fuel pressure. The spring in it may be weak, or broken.



Now, if that is OK, I bought my lift pump from the Case-IH dealer. Less than $100, including the 2 gaskets. You do need to swap one fitting from the old pump to the new one.



Lift Pump: J936317



Gasket: J939258 (two required)

 

[Joe G.]

Before you buy a bunch of expensive parts you don't need read this:

http://dieselram.com/ubb/ultimatebb.php?ubb=get_topic;f=45;t=000007



Remember the lift pump won't pump air. An air leak is the most probably cause of low fuel pressure. The overflow valve can also cause low fuel pressure. Test it by clamping the return fuel hose with pliers. If there is an increase in fuel pressure then the OF valve is bad. The lift pump is the least likely thing to cause a low fuel pressure problem.

 

[wildmanben]

Sweet, someone else buys parts for their truck at the case dealer...

 

[Matthug]

Yeah the 12v lift pumps very rarely pump that low, it may even be a combination of overflow valve and lift pump. I had low pressure, 10 PSI at idle, replaced overflow valve and bam 22 PSI at idle. But when my pump was going bad 2 months later I still had good idle pressure (22 PSI) but my pressure at 2000 RPM (no load) was only 26 PSI. Replaced pump, 34 PSI at 2000 RPM now.

Or, how long has it been since replacing the fuel filter or checking the pre-filter screen? This is the first place to look instead of buying a $60 overflow valve and a $100 lift pump.

 

[Signal73]

dont forget to check the basics like pre filter screen and fuel filter.

If your local, (I see mass diesel in sig) bring it to coffee night well get you figured out.

 

[PRattenbury]

Sounds like a good idea. I've been meaning to get to coffee night. I think I may just do that this Friday. Scott at Mass diesel told me about the prefilter screen and so forth. Bleeding the fuel system after putting in a new fuel filter took a really long time. He put a gauge on the pump and figured I probably had a lift pump issue. I'm going back up there on the 22nd, and will probably have delivery valves installed. It'd be good to have the problem solved before then so bleeding won't be such a pain. Pretty tough on the starter. What should I bring with me? A lift pump and overflow valve?

 

[Signal73]

Id start with a overflow valve and go from there. Mine was in pieces at 105K. Like Joe mentioned clamp off the return line if you have a guage installed inline to see what your PSI is, mine clamped off is in excess of 60lbs.