Community Forums

jacwjames · 11-04-2020, 07:52 AM

For those of you that have had a leaking diesel transfer pump, did just tightening the 3 bolts solve your problem.

If you changed your pump did you go with OEM or aftermarket. If aftermarket what brand did you use.

Mine started leaking, tightened the bolts which stopped the leak in the short term. Started checking on a replacement pump but Cummins thinks a lot of their pumps, about 2X the price for aftermarket.

Randy125 · 11-04-2020, 08:01 AM

Not sure which engine you have but look at extreme diesel on the internet.

jacwjames · 11-04-2020, 08:10 AM

Thanks, I'll check

It is the Cummins ISC350 8.3L.

The pump is a known problem and just started leaking on mine. After tightening the 3 bolts I cycled the key ~20 times while I also worked on some other problems. I'll check it again this AM.

153stars · 11-04-2020, 11:05 AM

Here is the gasket I believe no longer available from cummins.
https://www.ebay.com/itm/122561159521

wamcneil · 11-04-2020, 02:26 PM

I tightened the three bolts a few months ago and have not observed mine leaking since.
My primary symptom was a small puddle of diesel under the right side of the engine, but only after shutting the engine down. It didn't continue to leak but would reappear after running the engine and then shutting it down.
Every once in a while the engine would start and then die a few seconds later. Then was fine after restarting.
Capito Volvo in Montgomery AL has the gasket:
https://www.truckpaper.com/parts/sea...number=4928511
Cheers,
Walter

jacwjames · 11-04-2020, 02:48 PM

I've already got a spare gasket but decided to try and tighten the bolts first.

Makes sense that it would leak after the engine was shut off, the CAPS injector pump was pulling fuel through the transfer pump so it was under negative pressure.

The big issue is if the transfer pump leaks then it is also a potential place for the injector pump to suck air. Air in the injector pump can cause cavitation and big problems.

I checked mine again this AM and it hadn't leaked. I'll keep an eye on it for now.

Ken C · 11-04-2020, 03:27 PM

On our prior coach with the ISC 350, the lift pump started to leak. I tightened the bolts which stopped it from leaking which lasted about 1 1/2 years before it started leaking again. Had it replaced at that point. The pump only runs for 20 - 30 seconds when the key is turned on and was the only time ours would leak.