Community Forums

Dortzy · 06-29-2021, 01:35 PM

I have a 2005 Winnebago Journey WKP32T. Cummins 300HP
I have had the lift pump fail on me twice and would like to know if anyone out there has ever had lift pump relocated?
The remote mount lift pump kit, (from Cummins) Part Number 4955799, is for use on ISB CM850 engines.
This kit relocates the fuel lift pump, located on the engine, behind the ECM cooling plate,
to a remote location off the engine. Removing the lift pump and mounting it remotely
reduces the amount of heat and vibration to which the lift pump is subjected.
Cummins Installation Instruction Number is 4907748.
If anyone has had this done or has done it on there own please let me know how it turned out.
I have purchased the kit and I'm trying to figure out the best place to locate it. Having this pump in an easy to get at location will make it so that I can replace this pump by myself while on the road.
Thanks for any help.

Ray,IN · 06-29-2021, 02:44 PM

The lift pump only runs for 30-60 seconds after the ignition key is turned on, then the main pump assumes fuel flow. If your lift pump has failed twice I must ask, did you also replace the transient suppressor diode? It must be replaced at the same time as the lift pump or main injector pump.

Dortzy · 06-30-2021, 07:56 AM

I have had the repairs done at a Cummins repair center is SLC Utah. There was no mention of the diode being replaced. They have admitted that these lift pumps do have a high failure rate because of the heat from the engine. They indicated to me that this lift pump runs continually after the engine is running in order to supply fuel to the main, high pressure pump. They did replace a pressure sensor. So where would a diode be located?

Ljwt330 · 06-30-2021, 09:20 AM

Quote:

Originally Posted by Ray,IN

The lift pump only runs for 30-60 seconds after the ignition key is turned on, then the main pump assumes fuel flow. If your lift pump has failed twice I must ask, did you also replace the transient suppressor diode? It must be replaced at the same time as the lift pump or main injector pump.

He has a 2005 ISB which is a High Pressure Common Rail fuel injection system. It has a lift pump like the CAPS system, but it is different that a CAPS lift pump, as is the main injection pump as well. The lift pump on these engines runs continuously once the engine is running.

I can't comment on if diode replacement is necessary or even if a diode is involved in Common Rail engines, so you're response may be accurate after all. I'm only chiming in because your signature shows an ISC with which you are familiar.

Ray,IN · 07-01-2021, 02:52 AM

Quote:

Originally Posted by Ljwt330

He has a 2005 ISB which is a High Pressure Common Rail fuel injection system. It has a lift pump like the CAPS system, but it is different that a CAPS lift pump, as is the main injection pump as well. The lift pump on these engines runs continuously once the engine is running.

I can't comment on if diode replacement is necessary or even if a diode is involved in Common Rail engines, so you're response may be accurate after all. I'm only chiming in because your signature shows an ISC with which you are familiar.

Thank you for enlightening me! That makes everything i said immaterial because it doesn't apply to his engine.

camping fam · 07-06-2021, 08:36 PM

On my 2006 cross country with the 300isb I did the relocation kit from Cummins, added a pressure gauge, basically drove watching fuel pressure, rpm, and speed in that order still went through 2 more pumps, there is a hidden inline fuel filter above the rear axle (I did a right up about on here sometime ago) recently did away with the in-line filter and added an airdog system at the tank best thing I ever did and yes I left the factory lift pump in its place response is a lot better.

Dortzy · 07-07-2021, 08:11 AM

Thanks for your reply.
You know I cannot find that inline fuel filter on my frame. I have not taken it to freightliner but I have ask the Cummins repair facility to find this fuel filter. They say there is not one on my Motorhome, maybe because I'm only 33'. I have read posts about people removing theirs. I probably read your post. So could you tell me which airdog system you installed? Also you said that you installed yours at the fuel tank and did not remove the factory fuel pump, is there no fuel restriction running through the old pump?
Thanks again

Ljwt330 · 07-07-2021, 07:12 PM

Quote:

Originally Posted by Dortzy

Thanks for your reply.
You know I cannot find that inline fuel filter on my frame. I have not taken it to freightliner but I have ask the Cummins repair facility to find this fuel filter. They say there is not one on my Motorhome, maybe because I'm only 33'. I have read posts about people removing theirs. I probably read your post. So could you tell me which airdog system you installed? Also you said that you installed yours at the fuel tank and did not remove the factory fuel pump, is there no fuel restriction running through the old pump?
Thanks again

I had one on my 2007 coach, Freightliner chassis and 300 hp ISB. It was a 33’ MH.

Passenger side, in the frame rail by the air bag, you’ll see lots of fuel line and wire looms zip tied together in that area. I had to cut some ties and separate the looms and fuel lines to see it as it was buried behind.

Not all Freightliners had the filter, so the information they gave you may be correct.
Goolge, Racor 025-RAC-10

Wild Card · 07-07-2021, 08:14 PM

You can plumb in a FASS or Airdog system

Dortzy · 07-08-2021, 10:38 AM

Thanks for all the help. I will take another look this weekend. I will try and get a friend over to help me remove the rear right tires if I cant find it.
I will post an update as to what I find.

Ljwt330 · 07-08-2021, 04:21 PM

Quote:

Originally Posted by Dortzy

Thanks for all the help. I will take another look this weekend. I will try and get a friend over to help me remove the rear right tires if I cant find it.
I will post an update as to what I find.

No need to remove any tires. It is on the inside of the frame, inboard of the wheels. Look above the right rear axle area.

As I mentioned, not all chassis had the filter (actually a strainer), but those that did, it was very well hidden.

Dortzy · 07-13-2021, 08:15 AM

Yes I did find that out, and I did find that darn fuel filter. What a pain to remove. However thanks to everyone that commented I now have it removed and bypassed.
My next question
I am looking to install a new AirDog lift pump the kind with the 2 filters that purges the air from the system.
Does anyone have any pictures of one of these installed, also I am trying to figure out what to do with the fuel return line from the AirDog to the fuel tank.
There must already be a return line somewhere and if so can this be tapped into?
As you can probably all tell I am new to iRV2 not very good at navigating through the Threads.
Thanks so far for all the help.