OK. This is my first post. Hope I do it right. I determined that my LP was not working. I removed it today. First I could not get the output tubing off without twisting the tubing. I had to remove the input hose and then remove the mounting bolts from the pump and then twist the pump off of the output tubing. What a pain. While trying to work the plunger out of the block with the tubing still attached to the pump, the plunger fell out and hopefully into my oil pan. I'd like for someone who works on these engines to tell me that the plunger had nowhere else to go but into the oil pan and that I can just leave it in there. That's what I hope to hear. If there is a chance of damage then I need to know so I can get to work removing the oil pan.

Also when I called cummins in Arlington to see if they had LP #3925856 I was told that I would have to use #4988748. He asked if I wanted the spacer and 2 gaskets. I told him there was no spacer between my pump and the block. Does anyone know if the new part number requires the spacer or if that is for a different application?

 

If the new LP calls for a spacer you will need it unless you have the fuel heater strainer.
The plunger should have dropped to the bottom of the pan. You can try fishing it out at the next oil change.

edit
You should order a new line from the lift pump to the fuel filter, too. You probably twisted the line trying to get the fitting loose. About $50 from what I recall.

 

I did twist the tubing a little and am worried about it a little bit. I don't think the tubing split. I'm not sure who to order it from. It is an OSHKOSH chassis which was bought out by Freightliner so I guess I will have to give Freightliner a call. It looks like a banjo fitting where it connects to the fuel filter housing. I was sure not wanting to have to replace it.

As for the spacer on the LP I will carry my old pump with me to Cummins monday and compare them. The motorhome does not have the heater like the dodge pickups do.

Thanks for the help.

 

Go to Cummins. The fuel system from the LP is part of the Cummins module.
The line is much easier to replace than it appears. Been there done that.
If you want to try an re-use the old line, you need to get the swivel completely loose from the steel line and use steel wool to polish the ferrule. I didn't replace mine at first, but the fitting kept coming loose so I got a new line from Cummins

You are missing an important part of your old LP to use for comparison with the new unit, the plunger in the bottom of your oil pan. The spacer is there to get the correct cam lobe distance.

 

That makes sense about the spacer. If the new plunger is longer than the old one I would need a spacer to make up for the extra length. I'll dump the oil and see if I can get the plunger out that way. Or I could just see if the lp will bolt up. If the plunger is too long i should not be able to get it on. I will also get the new tubing from cummins. Thanks a lot for the help. It will be a few days before I can work on it again and then I hope to announce I'm up and running again.

 

I fished the plunger out of the oil pan. Went to cummins and bought a new pump without the spacer. Bought a new piece of tubing for the fuel filter. Installed it all, primed the pump quite a lot. Cracked all of my injectors. Cranked the engine twice about 15 seconds and got fuel out of one injector. Tightened all the injectors and hit the crank again and it started right up. Thanks for all the help.

 

Glad to hear it running. happy trails!

 

When I read your first post I almost fell outta my chair laughing. Not being cruel, but I just did the same thing Saturday! I tried slipping a magnet on a flexible shaft thru the LP hole and down into the pan but to no avail. How did you fish it out? Is the drain plug big enough for it to pass thru?

Vince.