Community Forums

dog walker · 06-24-2019, 08:15 AM

I seem to be having a reoccurrence of a lift pump problem. Had to have it replaced by Cummins a few years ago. Very costly to have Cummins do it. My son wants to tackle the replacement.

My coach is a 2003 Holiday Rambler Neptune with a Cummins 300hp ISB. Has 110,000 miles.

Is the lift pump on the engine or is it near the fuel tank?

Is this a repair that is reasonably straight forward? He is pretty good with this sort of thing.

Ljwt330 · 06-24-2019, 08:44 AM

Lift pump is on the engine, just above the starter motor. On a pusher, that would be passenger side.

I've never done the repair, but it is very common. Do a search and I'm sure you will find many comments/descriptions of the job as well as videos.

vito.a · 06-24-2019, 11:38 AM

There are several threads on Cummins lift pump issues in the Cummins section of this forum.
http://www.irv2.com/forums/f123/isb-...mp-387418.html

Several folks have installed an aftermarket Fass electric pump that pushes fuel to the Cummins lift pump and prevents future failures.

http://www.irv2.com/forums/f123/lift...de-397365.html

The above links will get you started. Go to the "Search" drop down menu above left and open it to "Advanced Search". Select the "Cummins" forum under Power Train. Type in lift pump in the search box and select "Search Titles only".
You will find a wealth of information on replacing and upgrading the lift pump.

jacwjames · 06-24-2019, 04:47 PM

The lift pump was a problem and Cummins put a TSB on it. Initially they replaced the pump proactively but then just started changing the gasket, and finally just the owner take care of it themselves. Now they only sell the pump as an assembly.

I did find a source for a gasket based on the info on the TSB, part # 4928511. Bought one from Capital Volvo in Montgomery AL 334-262-8856. Cost ~$8. I carry it as a spare in case my lift pump starts leaking and just tightening the bolts doesn't help.

Ivylog · 06-24-2019, 05:02 PM

When I replaced the lift pump on my my ISL, Cummins told me I only need to replace the pump (3 small bolts) not the entire housing and pump...NOT ! Fuel everywhere when I turned the key on so there is two different gaskets. Still worth buying one but it may not be the correct one. This was in 2014 on a 03 engine.

mlh2013 · 06-24-2019, 08:29 PM

I changed mine myself last year on my ISC, not a bad job fairly easy to do yourself. I bought the pump from Cummins I think for around 375 or 400 dollars, you might find it for a better price some place else. Some on here have said they just tighten up the 3 bolts on it and that solved there leaking problem, I didn't try that I just replaced it with a new one. Mine was located right above the starter, I accessed it from the top side of the engine through the hatch in the bedroom closet on my Windsor.