Dozer Fuel Injection pump Leak

BlueNoser,

I am not seeing the picture that you posted do you have a link to it?

What is the model# on your pump?

I would start with draining and refilling the oil in the injection pump.Then see how fast it overfills.

I have not had to tear mine apart yet. so I am not sure of the path that the diesel may be taking . If you the to the “nothing to loose point” (have to replace it anyway).  Try replacing he oil with a good auto trans seal sweller product. I have had amazing results with some of the berryman Trans sealer. Of course it is best to address the cause of the leak but my 1963 Case 320B Power steering I have been keeping a significant leak at bay for 20 years with that stuff. So while it is not considered a permanent fix sometimes it can do amazing things. I can let the tractor set for 3 months and not have to add a drop. Before adding it it would run out in a couple of days.  Good Luck!

Jim B

The fuel cavity (chamber) which floods the individual injector pumps is separate from the oil reservoir so that is unlikely the cause. The fuel lift pump piston doesn’t have sealing rings, it’s just a good fit (not a lap fit) and has an O-ring seal on the push rod that attaches to the cam follower. This O-ring is the only seal between the diesel fuel and the oil reservoir. You can remove the lift pump and disassemble it to change the O-ring. Unfortunately there is no manual for this but it’s a fairly simple task.

I had similar issues but when I disassembled my pump I found the check valve seats were badly pitted and the piston was badly worn due to diesel bugs. I wound up re-plumbing the primary fuel system and ordering a new lift pump from Tommy. Problem solved. You can also use an electric fuel pump designed for diesel fuel in lieu of the mechanical lift/primer pump as long as you have a fuel return line back to the tank directly from the fuel injection pump (the return line can also pass through the injector leak off lines).

Hi Blue,

Long time, no see.

My ordeal was detailed in the old forum with pictures and videos. I think the videos are still up on You Tube.

Bob,

If I understand your response you had trouble with diesel and oil co mingling in  the injection pump oil sump and the cause was a leak in the lift pump.

The leaking could be caused by a worn o-ring that is part of the lift/primer pump but in your case the pump was damaged by corrosion so you had to replace the lift pump instead of repairing it?

Thanks

Jim B

The check valve seats were not replaceable/repairable in my case, there is one for the inlet and one for the outlet. They were both pitted beyond repair with lapping techniques. And as I stated, the piston was badly worn. The 6mm O-ring would have cost me six cents and I didn't want to go through the trouble of building and fitting a new piston when a brand new pump assembly was only $35.00.

Diesel bugs are a very bad thing. I have personally witnessed them bring a 10,000 HP diesel plant to it's knees, and the ensuing repair costs.

I'm pulling the plug too, Tuesday.

That does it Bob, I've got to make a point of stopping by to see you next time I'm in the area. Congratulations, well deserved.

Congratulations, Bob!

Just finished my last night shift and I feel like I just lost 75 lbs. WOW!

Just wish I looked like it.

Bluenoser

I discovered this on my Jinma 284 earlier today.  Fuel leaks out around the cap on the top.  Looks like a similar spot, but I am unsure.   Anybody have any corrective suggestions to stop the fuel from leaking from the bottom side of this top cap?

Missouri,

You have the same issue as Blue. If fuel is coming from the vent cap, the entire sump is full of diesel fuel. Drain it all out and refill with fresh oil. Check oil level daily. Shut off fuel at the tank after each use. Decide if you want to repair it or just live with it knowing it will eventually fail.

Thanks. Seems like I work harder now and make less money.

I assume you mean just the lift pump, right? No need to pull the whole injection pump assembly.