Injector pump leaking diesel into the pumps oil tank

[Paddy]

Hello all,

I have been getting my KAMA 454 ready for winter. I changed the gear oil in the axels and tranny, Changed the engine oil. Filled the fuel tank. Then the bad news came when I pulled the dip stick for the injector pump! Diesel shot out of the dipstick hole. I mean it just flows out like a fountain 1 inch high. It stops when I put the dipstick back in.

The fuel tank is fuller than I normally keep it, so fuel lever is a lot higher than the injector pump.

I checked the engine oil and it's right at the full line, so does not look like its going there. Or much yet.

Left side is the oil side.
Questions;
Can diesel be dumped in to the engine oil?
Is there a seal that separates the injector oil tank from the fuel that can be replaced??
Anyone do a seal repair?

 

[Bob Rooks]

That's a pretty weird setup you have there. The fuel return is going back into the lift pump instead of the top of the fuel tank - who did that? But to answer your question, there are no seals between the barrel and plunger assemblies and the oil sump. The sealing is done by lap-fitted barrel and plungers. Having a small amount of fuel in the oil sump is normal, that's why it's changed frequently. But to have that much fuel indicates you have badly worn assemblies, or you aren't checking it frequently enough (should be a daily thing, just like engine oil).
If you drain the sump does fuel continue to flow out? Also, I don't see a secondary fuel filter anywhere, got one?

 

[Paddy]

Bob,


The KAMA has a fuel return to the tank off the injectors. The lines on the injectors were replaced early on but are just the way it came. I did add a spin on fuel filter many years ago

I will put a pan under the pump and pull the drain with the tank shut off. My gut feel is a lot of fuel will drain out. I have been using compressor oil. I changed it about a year ago but it has only run 15 hours from last change. After draining would using regular motor oil seal better? is there any danger diesel fuel can make it to the engine oil?

I see on Alibaba I can get an OEM replacement pump for $100. Shipping who knows right now.

 

[Bob Rooks]

Using compressor oil in the injection pump/governor assembly is complete BS, and only touted by one tractor dealer that I know of, and in communicating with them they could not tell me why they call for it. Just use the same oil that's in your engine - that's what every engine manufacturer recommends and does.
The return line from the injectors is just for the leaking weepage because the injectors are lap-fitted also. Usually that return line at the injection pump connects to the first injector. If you have a lot of fuel in the sump then I suspect the O-ring has failed in the lift pump. That has happened to me and others as well (no, the fuel will not get into the engine oil). The O-ring is a .50¢ part, but it's kind of a hassle to replace, and it will likely fail again in the future. The best solution I have found is to completely replace the lift pump with an electric fuel pump designed for diesel fuel. It works perfectly. My Mitsubishi excavator came plumbed like that from the factory.
This is the one I used on my TY395E engine in the dozer.

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[jacques54]

Using compressor oil in the injection pump/governor assembly is complete BS, and only touted by one tractor dealer that I know of, and in communicating with them they could not tell me why they call for it. Just use the same oil that's in your engine - that's what every engine manufacturer recommends and does.
The return line from the injectors is just for the leaking weepage because the injectors are lap-fitted also. Usually that return line at the injection pump connects to the first injector. If you have a lot of fuel in the sump then I suspect the O-ring has failed in the lift pump. That has happened to me and others as well (no, the fuel will not get into the engine oil). The O-ring is a .50¢ part, but it's kind of a hassle to replace, and it will likely fail again in the future. The best solution I have found is to completely replace the lift pump with an electric fuel pump designed for diesel fuel. It works perfectly. My Mitsubishi excavator came plumbed like that from the factory.
This is the one I used on my TY395E engine in the dozer.

Amazon.com: Autobest 12D Externally Mounted Universal Diesel Electric Fuel Pump : Automotive

Buy Autobest 12D Externally Mounted Universal Diesel Electric Fuel Pump: Electric Fuel Pumps - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

Your pump look like the same as on my FOTON. When it did leak like your's, I'd instaled an electric transfer pump from Amazon and a in line see throu mesh filter before. Cheaper than replacing the OEM lift pump and solve the fuel problem of oil in the injection pump.
Make a plate where was the lift pump then put new 15W40 oil in the injection pump. And like Bob said, the return from injection pump should return to the tank to help when bleeding the system. Weird plumbing fuel return.
Jacques

 

[Paddy]

Thank you Bob and Jacques,

good suggestions. Is the return line shown by the Red arrow? Is the lift pump where the primer pump is? Or on the left side?

what line would the electric pump be added?

Regards to bleeding, there is a hex nut on top that works fine with the hand primer.

 

[Bob Rooks]

You can connect the electric pump to the key switch.
Note: These are not unit injectors, so there isn't circulating fuel. The fuel returned from the injectors could be measured in droplets. And with the electric pump pressure set at around 5-7 psi it will be more than adequate to keep the fuel cavity full without opening the pressure relief valve. You'll be good to go.

 

[Paddy]

Bob,

Thanks again for all your help.

Your bottom most note; that line comes from my spin on fuel filter. So it looks like I connect the yellow hose to the intake of the electric pump then goes to secondary filter. Then connect the outlet of the 2nd filter to red line. Green line gets moved to discharge back to tank, (all injectors are "daisy chained back to tank so just "tee" on)

Remove hand primer completely. What will the new plate retain, oil or fuel?
The electric pump will provide prime pressure when bleeding.

Oil tank on injection pump to get engine oil. Will the oil still get diluted by diesel? Or the fix above stop this?

 

[Bob Rooks]

Bob,

Thanks again for all your help.

Your bottom most note; that line comes from my spin on fuel filter. So it looks like I connect the yellow hose to the intake of the electric pump then goes to secondary filter. Yes, if you want to add another spin-on filter for the secondary filter. This point gets the finest particles. Your fuel can never be too clean or dry (moisture free).
Then connect the outlet of the 2nd filter to red line. Correct. Green line gets moved to discharge back to tank, (all injectors are "daisy chained back to tank so just "tee" on) Correct.
Remove hand primer completely. Yes. Will the new plate retain, oil or fuel? Just the oil. The fuel cavity is up where the barrel and plunger assemblies are.
The electric pump will provide prime pressure when bleeding? Yes. More than adequate. Oil tank on injection pump to get engine oil. Will the oil still get diluted by diesel? No. This removes the source of fuel dilution. Or the fix above stop this? Yep.

 

[jacques54]

Well explain Bob.
Better that I could be able to do on computer.
Jacques