Diesel fuel leak when engine running above idle 1500D

[BenM]

When operating my tractor today, it began to stream fuel out of a hose that looks to be an overflow (see picture). It only happens above idle. The tractor has been sitting for a month. What is the overflow for, and what problem does the leak indicate?

Thanks.

 

[winston1]

I'm just thinking outloud. Wonder if that could be like a weephole on a water pump except it's on an injection pump? I'm not familiar with a 1500 and my 2002 doesn't have that hose. I'm sure somebody has a solid answer for you. Good luck!

 

[California]

That should be the crankcase breather. If your crankcase is full of diesel, it sounds like the injector pump is shot. Don't run it that way - the oil is too thinned out!

Is your fuel tank suddenly down a gallon or so?

 

[BenM]

Good call California! I pulled the dipstick, and the level is high, and the oil is thin. You mentioned that this could indicate a faulty injection pump. I suppose it's possible that fuel is bypassing the IP pistons, and out the bottom, but it seems to me that would cause the engine to be starved for fuel, which it doesn't seem to be. I noticed that there is what appears to be a petcock on the fuel strainer bowl, as indicated in attached picture (lever is snapped off). I have been out of town for the last 5 weeks, and I didn't close the petcock. Is there a possibility that the fuel could have leaked into the engine somehow over that period of time, or does that point back to the injection pump anyway?

Finally, if I have to replace the IP, mine has threaded fittings for the injector lines and a banjo connector for the fuel supply. The replacement at Hoye Tractor mentions that the model they sell has threaded fitting connections, but the picture looks the same as mine. Has anybody bought one of these, and does it look the same as the one in the attached picture?

Thanks for all the help.

 

[California]

I am confused by your photos. Is that a 'Vietnam Rebuilt' tractor?

On my similar Yanmar the fuel shutoff is at the input (left) side of the filter, the side nearest the fuel tank. Does that braided hose on the right side of your filter go up to the fuel tank?

And at the injector pump, I see two hoses - braided and plain. Where do they go?

 

[BenM]

I guess the pictures aren't the greatest. In the picture of the fuel filter, the non-braided line goes to the fuel tank, and the braided one goes to the injector pump. The lines you see in the second picture are the same ones, but the injector pump is hiding the filter. The previous owner said he replaced the line from the tank to the filter with the rubber hose. I compared the assembly with the fuel filter assembly (part 24 in the picture in my first post), and it appears identical.

As to the history of the tractor, I'm not sure. I bought it used, and it shows 175 hours on the hobbs meter, which looks weathered as though it was not replaced. I would guess it has been around at least once. At some point, somebody painted the hood and fenders and added a FEL, so it is entirely possible that it is a Vietnam rebuild.

What is the purpose of the fuel shutoff on the fuel filter? Is it just to shut off the fuel when changing the element, or is it intended to be shut off when the tractor is not in use?

 

[reb]

The pix look just like mine, except yours is too clean .

I don't know about the shutoff--I have never used mine (except maybe when I changed the filter several years ago). I thought it was stuck or locked with the screw above it in the housing until I looked at it a few minutes ago. At any rate, I have had no problem with fuel leakage into the crankcase.

 

[winston1]

The fuel shutoff is for filter change, not used otherwise. I hear of those handles breaking regularly. I open and close mine every once in a while just to keep it from freezing up.

 

[California]

... the injector pump is hiding the filter.

Oh! Sorry, I didn't understand what I was looking at.

 

[BenM]

I was hoping for the cheap route, but with the info from you guys along with another post that said that injection pump seal failure often leads to diesel leaking into the crankcase convinced me that the injection pump must be the problem. Has anybody had any luck with replacing the seals, or should I just buy the replacement unit from Hoye's? If I change the unit, will I need to adjust the injection timing, or can I use the existing shims?

Thanks.