Engine/Transmission (1994 - 1998) gear transfer pumps on side of Bosh inj. pumps vrs. lift pump.

[T. Baker]

I have seen Bosh injection pumps with gear transfer or lift pumps on the side of the injection pump body. This is the way most diesels with Bosh style pumps are done. Usually the gear tranfer pump is good for the life of the engine. I am wondering if there isn't a Bosh lift pump that we could just bolt on the side of our inj. pump and get rid of the short lived pulsing lift pump.

The pressure is always pumping up and down with each stroke of the lift pump and it wears the overflow valve spring out. Also the presure spikes make the engine lope at lower RPM idle I think. Also the return line tends to move with every pump and I had to wire tie it a bunch of places becase I was worried about it chaffing. I'm thinking about making an accumulator to even out the pressure pulses so that everthing will last longer and run smoother.

 

[Gary - K7GLD]

UMMMmm - the VP-44 already HAS a mechanical LP built into it...

 

[HoleshotHolset]

All of the Bosch inline mechanical pumps that I have seen with lift pumps bolted to the side are run off the camshaft inside the pump... .



I have one apart on my kitchen table.



Matt

 

[T. Baker]

OK Matt so can you tell us the part # or typical application for that pump and will it bolt on to the regular Cummins P pump?



Garry, not sure what you are talking about. I have read all over the place all the trouble you 24V guys have with that electric lift pump.

 

[Gary - K7GLD]

Actually, I'm right, and sorta wrong - I didn't recognize this post was from the 12 valve forum - but I'm RIGHT in that the VP-44 in our 24 valve trucks has a MECHANICAL rotary LP built into it - the EXTERNAL electrical pump is supplied to provide fuel priming and supplement fuel flow to the VP-44 - the VP-44 WILL run (and far too often DOES!) without the external LP functioning at all...



Sorry for any confusion...

 

[ronco]

The 370 horse marine engine has the low pressure lift pump driven by the high pressure P pump. My mechanic has one.



Ronco

 

[T. Baker]

So can I get one from Cummins or do I go to a Bosh dealer or both? Is it a gear pump or a piston pump. No point in changing it if it is bascically the same type of piston pump. Hasn't somone else done this yet?

 

[HoleshotHolset]

Ronco's right - the 370 marine versions have the lift pump bolted to the side of their P-7100's.



Normal (Dodge/Cummins) P-7100's don't have the provisions to run a mechanical pump off the side of 'em.



The pump I have is out of a Case bulldozer application... . so that lift pump is probably different than the 370 marine version.



98Rammer probably still has the lift-pump that was bolted to his 370 marine pump... perhaps he could get you a part number. BUT, that doesn't mean that you'll be able to just bolt it up to your Dodge/Cummins P-7100 version.



I'm not even positive that normal (non-marine) P-7100's have a lobe on the camshaft to even run a mechanical pump... .



Matt