I finally got into my 91 cummins to fix a major IP pump leak. I thought that it was the control valve but it's not. those O-rings looked fine but I replaced them anyway.
When I lay under the truck and have someone operate the primer pump I can see that the fuel seems to be coming from the two bolt cover in the the side of the pump next to the engine. could fuel be coming from there and would it be just the cover seal , or should there not be fuel in there at all?
It looks like I'll have to remove the pump to fix that.
Ray

 

Not 100% sure but there should be no fuel.

 

Yeah, it's that o-ring behind the timing piston cover. Very common leak and really easy to fix - AFTER you take the pump off the truck.

 

Hi
Please read my post.
I have had the same trouble with that cover.
TWICE
Once it came loose and the next time one of the cap screws snapped off.
Definately install new cap screws and locktite them in place.
It is a pain if you have to do it again.

Tim

 

Hi Tim

Do you happen to still have the part number for the pump seal kit?
Thanks ,
Ray

 

Tim, check to make sure that the KSB system on your truck is working properly.

Ray, the part number for the seal kit is in the sticky.

 

I am pretty sure the ksb is working. Truck starts fine and nothing has changed.
Just one of those gremlins that loosened the bolt the first time and an even bigger gremlin that probably tightened the screw to tight the second time and charged me for it.

HA HA

Tim

 

OK, don't spend 5 minutes to check it, what do I know? It raises the pressure on that plate when the KSB is actuated and you seem to be having a lot of trouble keeping the plate on.

 

I will check it but i think it is more of a matter of age.
Truck had over 240,000 when i got it and it came loose shortly after that.
I put over 100,000 on it when the cap screw broke and i can be pretty sure it was a weak bolt and was over tightened.
I would imagine that the pull out strengh of the threads in the aluminum pump body would be far less than the strength of that cap screw.
And if i remember correctly that is the same screw that came loose the first time.
This also may be a rebuilt pump as i noticed a lot of yellow paint under the outer black paint job?????
Anyway thanks for the concern.
If it goes another 100,000 i can't complain.
The rest of the truck will probably fall apart by then.

Tim

 

I was away for a few days and now finally got the fuel leak 0n my 1991 fixed. It was a loose bolt on KSB cover that let the O-ring blow out. wannnadiesel was right, it took about two minutes to fix AFTER I took the pump off. Thanks Tim, I did locktite the bolts.
This truck had not been run in six years, so I pulled the injectors and squirted oil into the cylinders before starting it up. I also turned the full fuel screw in two turns. After bleeding, The engine started and ran fine, and really strong.
When I stomp on the throttle at mid RPM in first gear (not granny) It will spin the tires on conrete. I'm not very experienced with turbo diesels but this seems amazing. Is it faster response because it's not intercooled;shorter/less voluum intake tract.
Tomorrow I'm going to look at and probably buy a 1952 M37 army truck.(military version of the power wagon) to put the body on this chassis or a 1990 4x4 Dodge with Cummins.
Thanks to all on this forum. I'd be lost without what I've learned here.
Ray

 

That's just torque. If you think it's responsive now, wait until we goad you into putting a 3200 RPM spring in it.