Fuel Tank Leaking on Kubota L4200

npaden · Oct 3, 2007

Well, I'm not sure what happened by my fuel tank is leaking on my Kubota L4200. I'm pretty sure it started on Saturday after mowing on some rough ground so maybe I stressed it or something.

I circled the area in red where it is leaking. It appears to be leaking from the inside of the hole where the bolt goes into the tank. The leak was fairly slow with a drip about every 2 seconds until I unscrewed that mounting bolt when I was working on removing the heat shield to see if I could find the leak and then it started leaking much faster and was running out of the hole where I removed the bolt. Probably 2 or 3 drips per second after removing the bolt.

Here's a picture from the parts diagram:

The fuel tank is a $500 part from Kubota so I'm wondering if there is a way to fix this without buying a new tank. Removing the tank looks like it is going to be a chore all by itself so I would love to be able to fix it with the tank still on the tractor but I doubt that will happen.

One thought that I had was to let it dry out (I drained the tank down past the leak after I found it) and then squirt some silicone in the hole and put some teflon tape on the mounting bolt and just put it back together and see what happens. That would be cheap and easy but not sure if it would have much chance of working or not, and not sure how long it would last if it did work.

The other thought would be to pull the tank and somewhere in the dark recesses of my mind I seem to remember hearing someone talk about getting their fuel tank "re-lined". Has anyone else heard of that?

Any other thoughts or suggestions?

Thanks in advance. Nathan

BTDT · Oct 3, 2007

Take it to a radiator shop. They can clean, repair, and have you going in no time. Probably for less than a hundred dollars. Call around if your in a large metro area, should be several to choose from.

dbdartman · Oct 3, 2007

If the tank is metal, you have options:

Weld

Solder

Coat

Epoxy patch

Replace

The best cheap "permanent" repair would be a tank lining. This is available from many sources (Eastwood & Bill Hirsch are two that immediately come to mind). I did a tank in one of my brother's old station wagons with this once. Remove the tank, dump it, clean it with brake cleaner, pour the tank liner in (it's a liquid), tip the tank around so the liner coats all internal surfaces, pour the excess out, let the liner dry for a day, & reassemble. Most radiator shops will coat tanks also, plus solder/weld.

Least expensive repair would be to pick up some gas tank epoxy from an auto parts store.

Plastic tanks are a little tricky, but there are epoxy patch kits available, & the other option (aside from replacing) is to melt/weld.

I wouldn't count on silicone sealing it, & even if it did, most silicone will deteriorate when exposed to gasoline (I suspect it will also deteriorate it, but will take longer). I'd also warn against using teflon tape anywhere on a fuel system. You WILL end up with bits of teflon floating around in, & wreaking havoc with, the fuel system!

Soundguy · Oct 4, 2007

If it was mine, and metal.. I'd consider a solder ptch.. however.. depenfin n how it is leaking.. and wher ethe place is.. jbweld may even work ( it is fuel proof once cured )

If it is a blind hole that broke thru you have plenty of options.. perhaps a fuel rated thread pucky ( make it for gaslines and such.. yellow paste ) that and a nitrile fuel rated oring under the bolt head ( lube the oring )..

DON'T use the sliicone and thread tape.. you won't like the results!

soundguy

npaden · Oct 4, 2007

Well after 3 hours of wrenching this morning the fuel tank is in the back of my pickup and I'm about to head to town to a radiator repair shop.

I need to take a picture of what you have to remove to get the fuel tank out! (Dash, Steering Column, etc., etc.)

Looking at the tank it may have been repaired before. One of the attachment bolts was missing also. Thinking from the positive aspect, I'm learning a lot more about my tractor!

BTDT · Oct 4, 2007

Since the tank is out of the way, and you now have some exposure to some things you couldn't see before, now might be a good time to give that area a good looking over to see if anything there needs attention (chewed, frayed wires, leaking lines, broken brackets, etc.). Good luck with the tank repair. Do you have an estimated cost yet, or will that be forthcoming when you get it to the shop?

npaden · Oct 4, 2007

Yeah, with the diesel leaking there is a lot of muck under everything that I'm working on getting cleaned up.

They estimated $55 to repair the tank but it is a tenative estimate, it could go higher if they have to do a lot of extra work on it but they will let me know if that is the case. They plan to clean and solder it if possible and re-lining it would be a last resort. Not bad compared to a new tank at $500+.

One thing I need to decide is that when I tried to get one of the hydraulic hoses off of the steering assembly I couldn't get it off a the regular connection so I tried to turn it and get it off at the base of the assembly and I ended up twisting the hose up quite a bit. I've untwisted it and can't see any obvious problems but I would hate for that hose to start leaking after I got everything all back together. What would the likelyhood of a hydraulic hose leaking because it got twisted?

I'm starting to wonder about this tractor. It supposedly had 927 hours on it when I bought it but I've done 2 repairs and both repairs I was the 2nd person in there. On my steering cylinder it had been southern engineered by someone and created some problems and looking at the fuel tank evidently it has leaked before and there is epoxy or bondo spread around in several places including the spot where it is leaking now.

Hopefully after I get this fixed I will be done fixing it for a while!

BTDT · Oct 4, 2007

Twisted as compared to kinked, twisted will probably be ok. But, hoses are fairly cheap, so it would be up to you, do you really want to go through this again to replace a leaking hose next week/month/year. Might as well fix it now and be done with it (IMHO).

If you or me or the rest of us didn't have a problem every now and then with our tractors/equipment, then there wouldn't be a need for this forum.

npaden · Oct 4, 2007

What about twisted AND kinked?

It is an odd connection on the hose and the OEM part is $70.00. I guess I shouldn't have twisted it. I didn't really think that twisting it could damage it until I looked at it after I got everything disconnected and saw it twisted up and kinked in about 4 spots.

I guess I could take it to a hydraulic hose shop and have them either check it out or cut the odd connection part off and splice it together with a regular hose that is the correct length?

Here is a picture out of the parts diagram:

What do you think?

Soundguy · Oct 4, 2007

npaden said:
Well after 3 hours of wrenching this morning the fuel tank is in the back of my pickup and I'm about to head to town to a radiator repair shop.

I need to take a picture of what you have to remove to get the fuel tank out! (Dash, Steering Column, etc., etc.)

Looking at the tank it may have been repaired before. One of the attachment bolts was missing also. Thinking from the positive aspect, I'm learning a lot more about my tractor!

I think that will be a good repair avenue.. pluss they will likely 'boil' the tank out befor ethe repair.. that is a bonus in itself right there. ya might have to clean and repaint it though.. but again.. another bonus.. it will be nice and shiny!

Soundguy