You CAN repair a leaky fuel injector pump! PICS and a question.

[ehenry]

I replaced the orings on each plunger and have put the everything back together, bled fuel lines and cranked the tractor. The tractor cranks fine, runs fine and there does not appear to be a leak at the top of the injector pump any longer. What I do have happening now is there is now diesel fuel leaking from the starter. I removed the starter and the flywheel has diesel on it. The higher the rpm of the engine the fuel from the starter slows down. The lower the rpm the more fuel leaks from there starter. As I said above, the tractor cranks and runs fine. No fuel is getting in to the engine oil either.

If anyone has any idea or clue as to what may be going on I would appreciate it. This was not happening before I replaced the orings on the plungers.

 

[KYKub]

It might help if you could post some pics.

Are you sure the diesel fuel on the flywheel didn't drip there while you were bleeding the lines?

Can you "follow the path" of the leak to identify the source or area it is coming from?

 

[ehenry]

I've cleaned the top of the engine with mineral spirits the best I can and can find no fuel leaking from the injectors in the head or from the fuel line. The rubber hose from the injector at the back of the engine that runs back to the fuel tank is not cracked. I guess I'm going let it sit until morning, check the oil to see if fuel is getting in to the oil pan. I'm afraid to run it very long if fuel is getting in oil. The oil level doesn't appear to rising for the short times I've run it to try and determine what is leaking.

 

[gwstang]

It might help to get a container of baby powder and dust around where you think it is leaking from. The source will show up well in the powder as it tracks downward.

 

[ehenry]

Here is a video of the lease. You can see the drip below the plastic fuse dripping off the cable holder and the bottom bolt of the starter.

 

[KYKub]

That is strange (not what you want to hear when you're looking for help). Obviously, the leak doesn't have anything to do with the starter; the fuel is just dripping from a lowest point.

All of the fuel supply, injectors, filters, etc. are on the opposite side of the engine. It seems like it almost has to be leaking at the top or other side and somehow finding it's way to the flywheel/starter.

Not being smart, but are you sure it's diesel fuel that's leaking? Could it be coolant? That would seem more likely to be dripping around the starter area.

If it is diesel fuel, it is probably leaking somewhere on the "fuel side" of the engine and finding it's way to the flywheel. The flywheel is then throwing it on the starter. That's a significant leak so it shouldn't be too hard to trace.

 

[ehenry]

I popped the instrument cluster off yesterday thinking maybe the fuel tank might be cracked or something leaking on top where the bellhousing and engine bolt together but its dry as a power house underneath the tank. I did loosen all the bolts around the bottom of the bell housing and a cup or more of fuel drained out. I let it drain until it quit and I rocked the tractor by hand and more dripped out. I let it sit for a couple hours then cranked it and the leak was considerably less. I bumped the rpms up to about 2500 and let it run for about 30 minutes and the leak all but stopped. I emptied and cleaned the bucket under the tractor then let the it sit over night last night. THis morning, the bucket was dry with only a drop or three in it.

This afternoon I plan on tightening all the bolts back up and just driving the tractor around my place for a while to see if the leak continues.

My question for this is how did the fuel get in the bell housing when the only thing I did concerning fuel was pull the plungers from the injection pump and replace the orings on the plungers.....WHICH....by the way was a snap and fixed the leaking under the flanges at the top of the injection pump.

 

[LarJea]

Thanks for the info. If I ever do this, I am going to use Viton O-rings also I believe the O-rings are metric.

 

[arto98607]

KYKub

I had a small leak in my fuel injector pump and read that self-repair of these units is impossible, or at least strongly discouraged. Having a brother that is a good mechanic and can bail me out of most of the messes I create, I figured I would give it a shot. My repair was to a 3 cylinder Kubota (D722), but I think the same basic process would work on any Kubota diesel engine. This seems to be a fairly common problem so I hope it saves some time and money for others.

The leak was around the base where the injector lines connect to the pump. Slow leak, but over time builds up oily junk down the side of the engine. The problem is failing O-rings on the shaft of the injector. 2 O-rings on each shaft. Here's what I did: ....zip




Thank you thread starter KYKub - your posting is appreciated!

I have exactly the same fuel leak in my Kubota F3060 mower (Kubota V1305 engine), and was able to find the O-rings on the eBay with the dimensions you gave by searching: Viton/FKM O-ring 11.8 x 2.4mm Price for 10 pcs


:jump:

 

[KYKub]

You're welcome! Glad you were able to source the o-rings. I don't have the machine any longer, but the repair was permanent. I hope yours is, too.