Leaking diesel fuel line

smithdenny · Apr 3, 2021

I have a 2014 Kioti DK50 with less than 300 hours. Late last summer I noticed a small puddle of diesel fuel on the garage floor. Leak was small so did not investigate further at that time. The leak has not gotten any worse but thought I need to fix the problem before the mowing season. This model has two plastic tanks mounted under the floorboards on either side of the driveline with several crossover lines between them. I was concerned the tank(s) may have had a crack based on another different model Kioti report I read here last fall when I mentioned this leak.
I removed several plates protecting the tanks and lines to find a great deal of grass, dirt and even a few small pieces of gravel packed in around this area (I spread 100+ tons of gravel last spring with this tractor but its used mostly for bush hogging). It appears the tanks are ok (thanks goodness) but the flexible fuel lines are oozing fuel with a drip about every 30 seconds (much faster now since I cleaned out the debris from the area moving the lines as I did so). The lines are original and appear to be a rubber hose covered in a (nylon?) fabric. There are 2 lines from each tank to a tee which then runs up to the engine. The lines are attached with a SS hose clamp at all locations.
I can replace the lines without too much problem I think (hope) but what type of line is the best recommended for long life? The plastic tanks have a molded barbed outlet so will need to clamp a hose to them. More importantly, what caused the problem? Certainly a possibility is a hole caused by the debris but it appears to me at this time (have not removed the lines yet as I write this) to be a general breakdown of the rubber oozing fuel.

BravoXray · Apr 4, 2021

Asking the obvious, but did you try tightening the clamps?
Some look like they would be difficult to tighten.
Regular fuel line like NAPA carries will do fine with diesel fuel.

denchen · Apr 4, 2021

For smaller diameter of pipes, I do not like the type of clips you have on your pipes. I think that the part where the screw is, is always flat and not a round pressure on the pipe. I would go for new pipe, and maybe what we call `double ear` clips. I usually nip these up with a pair of blunt pincers although you can get a proper tool. Failing that, some screw clips have a leading flat piece of metal that covers the area where the screw is.

Diggin It · Apr 4, 2021

smithdenny said:
More importantly, what caused the problem?

Vibration. I had the same thing happen. Cut the fuel line back a bit and reclamped.

Diggin It · Apr 4, 2021

denchen said:
For smaller diameter of pipes, I do not like the type of clips you have on your pipes. I think that the part where the screw is, is always flat and not a round pressure on the pipe. I would go for new pipe, and maybe what we call `double ear` clips. I usually nip these up with a pair of blunt pincers although you can get a proper tool. Failing that, some screw clips have a leading flat piece of metal that covers the area where the screw is.

They make what some call a fuel injector clamp that has a more fully round clamping surface. Not sure how large a diameter is available:

oosik · Apr 4, 2021

Had a very similar problem with the fuel return line. It had one of those round wire pressure clamps. Snipped off an inch and went with a "double eared" clip. Still good after five years. Bought "double eared" clips from the dealer. Also borrowed the special tool from service manager.

mini14 · Apr 4, 2021

If you replace the lines like to use marine fuel line. Its thicker. Has a heat resistant outer jacket

smithdenny · Apr 4, 2021

Thanks to all for your responses, they are much appreciated. After removing the lines, the tanks with the barbed outlet tubes look good. I can find no tank cracking which was my biggest concern. I am in a rather rural area (by choice, finally escaped Atlanta after too many years!) so usually find UPS delivery is cheaper than running into town. Ordered new hose along with the clamps "Diggin It" suggested. Should get parts in mid week or so.

An interesting side note. The fuel lines are protected by two metal plates (shields) that were originally secured with three screws. Two of the screws on each plate were removed apparently by the dealer for FEL bracket clearance. Not enough room for the screw heads. So the plates were secured with 1 screw with the other end of the plate resting on the FEL bracket. The plates were secured, had not moved so no problems. Won't fix what is not broken. But found it interesting the FEL bracket was not designed to clear the screw heads. I reckon the FEL engineers work on a different floor than the tractor engineers!

Thanks again for your responses, love this site!

CoyPatton · Apr 5, 2021

Diggin It said:
They make what some call a fuel injector clamp that has a more fully round clamping surface. Not sure how large a diameter is available:

I know you can get this general style clamp in larger sizes as I have used a heavy wire version on pool lines. However they ate difficult to find.
It tends to be the cheaper made hose clamps that have flat areas. Ask about hose clamps ad you buy new fuel lines at the parts store. If their is mot a curved portion under the cam screw, keep looking.