Engine/Transmission (1998.5 - 2002) lift pump leaking at wires

[jmtandem]

Has anybody had the lift pump on the 24 valves l(2001) leak at the bottom where the wires enter the pump? It is not the fuel line connectors leaking. Pressures are very good, 14-15 at idle, 12 at 65-70 mph. Thanks for any info you care to share.

 

[DLausche]

Has anybody had the lift pump on the 24 valves l(2001) leak at the bottom where the wires enter the pump? It is not the fuel line connectors leaking. Pressures are very good, 14-15 at idle, 12 at 65-70 mph. Thanks for any info you care to share.

Yep, had that happen on the 3rd LP about a year and a half ago. Decent psi, but was leaking and not at fuel connections. DC replaced it under warranty. I'm on 5th LP now.



-Deon

 

[JerryTurbo]

A Leak Can Be A Good Thing

The lift pump runs in fuel and what happens to the water in fuel?

Yes, its collected in the bottom of the pump body and it happens thats where the commutator end bearing is. I wished there was a drain valve in the bottom so water and rust could be drained off. Most LP failure is the end bearing going bad because of this trap.

 

[mhenon]

The lift pump runs in fuel and what happens to the water in fuel?

Yes, its collected in the bottom of the pump body and it happens thats where the commutator end bearing is. I wished there was a drain valve in the bottom so water and rust could be drained off. Most LP failure is the end bearing going bad because of this trap.

JerryTurbo... . that's interesting. I beleive that's the first time I've read anything about water sitting in the bottome of the LP. It sure makes sense though. Always thought there was more going on with these pumps then just poor design. Especially those guys with mutiple pump failures.

Most of the marine web-pages specify a filter first (100 micron or so), then the lift pump and then the final filter ( 30/10/2 micron). That way you're not forcing the LP to pump raw/dirty fuel. Wonder if this is part of the problem with the LP on the Cummins?

The 2nd generation engine is amazing though. If it wasn't for that $150. 00 lift pump thing. . there would be "almost" no problems. I can live with it.

Mike

 

[JWBoothe]

Has anybody had the lift pump on the 24 valves l(2001) leak at the bottom where the wires enter the pump?

Yup. I installed a new LP a few weeks ago and it immediately leaked from the electrical connection. The electrical connector was cracked during shipping and I put some epoxy on it thinking that it would have no bearing on its function. Beware!! Somehow that electical connector seals against the LP case and is a potential leak point!!

 

[lrox]

I just had the same problem on my lift pump. I parked the truck overnight and in the morning I found a puddle under the truck. My lp is completely dry except for the bottom where the wire connectors are. One week later the leak has not been seen at all. I have a spare LP in my tool bag in the truck just in case.

 

[JerryTurbo]

Water at 4 deg.

JerryTurbo... . that's interesting. I beleive that's the first time I've read anything about water sitting in the bottome of the LP. It sure makes sense though. Always thought there was more going on with these pumps then just poor design. Especially those guys with mutiple pump failures.

Most of the marine web-pages specify a filter first (100 micron or so), then the lift pump and then the final filter ( 30/10/2 micron). That way you're not forcing the LP to pump raw/dirty fuel. Wonder if this is part of the problem with the LP on the Cummins?

The 2nd generation engine is amazing though. If it wasn't for that $150. 00 lift pump thing. . there would be "almost" no problems. I can live with it.

Mike

Makes you wonder.

 

[jmtandem]

Jerry Turbo,



How many lift pumps have you gone through in 650,000 miles? That is incredible mileage for such a recent model year and a testimony to a quality product.

 

[JerryTurbo]

3 LPs and Flying J fuel. (dry)

 

[Gary - K7GLD]

IF you ever saw the internals of a LP - and comprehend the frantic agitation and fuel flow swirlng inside that motor housing. I think you might change yer mind on the water-in-fuel bit!



I've had a couple apart, each with over 100K miles on them and absolutely NO signs of water inside - and both the bottom shaft and bushing were in EXCELLENT conditio, NO signs of water or rust.



On the other hand, a few LP leakage problems above were with LOW miles - FAR too low for water to be a factor, even if it WAS in the fuel...

 

[JerryTurbo]

IF you ever saw the internals of a LP - and comprehend the frantic agitation and fuel flow swirlng inside that motor housing. I think you might change yer mind on the water-in-fuel bit!



I've had a couple apart, each with over 100K miles on them and absolutely NO signs of water inside - and both the bottom shaft and bushing were in EXCELLENT conditio, NO signs of water or rust.



On the other hand, a few LP leakage problems above were with LOW miles - FAR too low for water to be a factor, even if it WAS in the fuel...

I haven't seen the frantic agitation and fuel flow swirlng inside the motor housing.

But I can comprehend what happens when the pump is not running and water migrating to the bottom of the pump housing. No mind changing yet Gary.

 

[Gary - K7GLD]

UMmmm - not trying to "change anyones mind", only pointing out the conditions going on inside a LP motor...



Put another way, how much percentage of water volume would you assume was in circulation inside the LP at any given point in time? And how much would you suggest might "settle" to the bottom at ignition switch-off?



I can pretty much assure you that precious LITTLE percentage could possibly be contained in the volume of fuel retained inside the LP - and if there WAS, you would have FAR more to worry about than merely rusting out the pump shaft/bushings, or rusting out the LP bottom...



FOR the record, here's a shot into the bottom of a used LP with about 110K miles on it:



#ad




And here's a shot of the armature from that same pump:



#ad




See any rust or other evidence of water in there?



Neither did *I*!



(NO, I know THAT didn't change your mind either... )