B7300 W/D722 Engine Strange Fuel Leak

[ehenry]

I have a B7300 with a D722 engine. It has 2128 hours on it. I've got a problem and Ive absolutely no clue whats going on......There is diesel fuel leaking from the starter when the engine is running. I removed the starter and the flywheel has diesel on it. The higher the rpm of the engine the fuel leaking from the starter slows down. The lower the rpm the more fuel leaks from there starter. The tractor cranks and runs fine. No fuel is getting in to the engine oil either.

Anyone have an idea of what might be happening??

Thanks

 

[coachgeo]

look above it. Starter just may be where it leaks into the engine where the actual leak may be above starter and leaks down to the starter where it gets into the engine.

I'd check the overflow lines that run from injector to injector as well as the last of these lines which is usually a plugged line since it has no sister injector to run too.

 

[ehenry]

I have looked at all the injectors, lines from each injector. The head is dry as is the back side of the head. What I don't understand is that the flywheel is wet with fuel.

 

[ehenry]

Here is a video of the leak. You can see it dripping from the bottom bolt of the starter and the cable holder on that bolt.

 

[D2Cat]

Fuel is in the tank, goes to the filter, goes to the IP, goes to the Injectors, return line goes back to tank.

Those are the only places unburned fuel is present.

Clean and dry the entire engine area. Then follow each part of the fuel system. I'd guess it's a return line leaking. Or the line coming out of the fuel tank.

 

[nzzshl]

I'm thinking it's potentially a chafed or broken return line from the injection system. It doesn't sound like there's evidence of fuel spray, resulting from a pressured delivery line. On some diesels there is a fuel rail delivery system but I don't believe your's to be of that design. Wolfman might be thee guy to clear it up.

 

[North Idaho Wolfman]

Most likely it's coming from the line out from the tank or the tank itself, as it sits directly above the clutch housing and the fuel is probably seeping into a joint at the top of the housing and being pushed out at the starter.

You're going to have to dive into it and pull the tank and find the leak.

 

[ehenry]

Since the fuel tank is in front of the steering wheel, 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 loosened 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 cranking and letting it run a while longer and see if fuel continues to leak. If not, I'll tighten all the bolts back up around the bell housing and just start driving the tractor around my place for UTV for a few days to see if the leak continues.

Question is.....if the leak is gone, how did fuel get in bell housing and where did it come from.

 

[Lil Foot]

if the leak is gone, how did fuel get in bell housing and where did it come from.

Large fuel spill when filling the tank? I would still lean towards a fuel line or return line leak.

 

[ehenry]

I'll give a report later this evening when I get home and let yall know what I find.

 

[D2Cat]

I think the fuel you drained is just that which leaked into the bellhousing. You have to discover what is leaking to allow it to flow there.