8.3 L Cummins lift pump

[DeWayne]

I have a Case IH 8.3 L Cummins with an APF JV lift pump. This has failed about 7 times over the last 15 years and I repeatedly replace it with another expensive unit. So I have 2 questions. Why does it fail so often? There is not much inside these units. Do they make a rebuild kit? Thanks in advance.

 

[HHhuntitall]

I'm not sure what type of pump you are referring... is it a mechanical style like the 7120-7240 Magnum style tractor?

 

[DeWayne]

Yes it is a 7230 with a mechanical pump.

 

[DonFitzwater]

Have you done a restriction/air leak check on the fuel system portion between the tank and pump? Have you test low pressure output?

 

[HHhuntitall]

Failure rates are minimal in this application, in my experience. I've worked on quite a few, and actually have two of the Magnum series tractors, and have never had a failure on either, nor my 5240 with the 5.9L. Magnums are both over 5,000 hours, and 8,900 on the Maxxum. The only ones I've replaced have over 8,000 hours on them, so I'd have to say I'm curious what the problem is.... I've seen rampant failure in the old 12v Dodges that ran biodiesel or veg oil fuel... are you getting any biodiesel?

 

[DeWayne]

I have not made it back out to the shop yet but I am beginning to wonder if some foreign material is floating in the tank and when it gets this low it covers the fuel line somehow. Does anyone know if there are rebuild kits available for these fuel transfer pumps. Thanks

 

[petersonj]

Why does it fail so often?

Years ago I worked in a shop in a Colorado ski area and the company had a tow truck that was going through mechanical fuel pumps on a gas engine. After about the fourth fuel pump failure in as many years, I decided to cut open the last failed pump. I found a small piece of cinder holding the inlet check valve open. There was a lot cinder inside the fuel door (from sanding the roads) and small pieces were finding their way to the fuel pump. I installed an inline filter and the problem never occurred again.

I only mention this because the 8.3 Cummins lift pump operates on the same principal. If you still have the old lift pump, maybe you can disassemble it or cut it open and see if you can find the cause of failure.

- John

 

[HHhuntitall]

I do not know of any rebuild kits available, but if you open one up, it's pretty straightforward. If it's not galled or doesn't have any broken parts, it should rebuild with a few o-rings.

As for a pre-filter, these tractors come with a 200 micron inline brass screenstrainer, which looks like a small inline fuel filter for an old Dodge pickup, except it has 3/8" lines. Speaking of which, have you ever pulled that to see if it might be stopped up?