Fuel Tank Leak

[rwork]

Discovered I had a leak in my R3039H fuel tank today. Found a large puddle of fuel on the barn floor. After a closer inspection, it appears to be a tiny crack at about midway on the front side of the tank.
There is an indent which has a retainer bar across the front of the tank, located behind the seat, which is the location of the leak. I grabbed some plastic tank repair putty from the auto parts store, and tried that as a temporary fix, until I can recheck it mid-week. I have my doubts about it working.
Can't imagine what would cause it to just suddenly begin to leak. I've read of some people using a soldering iron to repair plastic tank leaks, put I guess I need to pull the tank so that I can see exactly what's going on. Even thought of trying some 5200 sealant.

Anyone have any experience with repairing plastic tank leaks?

 

[farmer2009]

I've repaired plastic tanks but never for fuel. They were always sprayer tanks.

I always used an epoxy tank repair kit and it would last for 12-18 months but always ended up replacing the tanks. Most leaks were in seams and molding corners. So hard to get a good repair.

 

[Tractor Seabee]

Plastic tanks can be welded. There is a hot air torch method as well as using a hot iron method. As in welding metals you have to melt and fuse the tank and the repair rod. It is more of a stirring process. Careful, too much heat and a blob will fall out same as welding steel. If you can O/A weld steel you should be able to master the air torch after a little practice. Works best in the flat position although, I have done it in other positions, even overhead. Harbor Freight has both types. Link: Search results for: 'plastic welding'

Ron

 

[bruceatlam]

Read through this thread:

http://www.tractorbynet.com/forums/...g/269040-r3039-fuel-tank-leak.html?highlight=

My latest update is that the new tank that my dealer had forwarded to me also developed a leak at that same seam/mold separation line. It wasn't in exactly the same location on that seam but it was on the same seam. I believe that I had a bad fuel cap. It wasn't letting air enter as the tractor used fuel --- as a result the tank started to form a vacuum and flexed that plastic tank wall which resulted in the crack at the seam. I eventually figured that out and bought a new cap which solved my problem. My epoxy seam repairs have held without issue. So far anyway -------------

 

[rwork]

Bruce, thanks for the reply. After looking at your pics, i believe that's the same spot mine's leaking. I've had my tractor a little over three years, so I'll likely try to repair it myself. Might try some 3M 5200 sealant.

 

[bruceatlam]

Same here --- a little over three years, if I remember correctly, you bought a couple of months after I bought mine. I'm just past a year on my epoxy seam repair. I check my fuel cap most every time that I use the tractor. I don't want any more fuel tank vacuums on a plastic tank.

 

[PILOON]

A soldering iron can be used to melt and fuse most plastics.At times I also have used hot glue guns to add more 'plastic' to the repair site.

Another product that I have had success with is windshield cement (in a tube) that they use when replacing car window.
Basically it is polyurathane caulk very similar to some brands of caulking sold at building supply houses.
One brand I often have used is FLEXTRA.

I even once patched a hole in a battery that I had dropped and otherwise would have been scrap.

As a test we once stuck 2 pieces of clean metal with that caulk (and plastic to plastic) and tried to pry apart. Virtually impossible!
Couple of weeks ago we patched up a rusty leaky old tractor fuel tank using the caulking technique and so far so good.

What sold me on the idea of that caulk was the lumber supply had a 'point of sale' device that consisted of a block of metal with sample color cords of the caulking that literally hung down from the block. Naturally folks would grab the 'cord' and pull.
Well I pulled that 10" cord and stretched it maybe 20" and it never let go.
If 1/4" glued to a block of metal had that kind of adhesion I knew that I found many new uses for it.

 

[bruceatlam]

FWIW, I've never had any luck "welding" plastic. Tried three or four times. The weld seam always seems to turn out brittle and then, as a result, cracks easily. I'll readily admit that I may not know what I'm doing, but for the time being, I'll pass on welding plastic.

 

[Threepoint]

Rwork, if your fuel tank is HDPE, which I suspect, it is a chemical cousin to paraffin wax. Sealers and adhesives just won't stick to it. :mur: In your case it sounds like the crack was caused by continual flexing of the plastic, and that's going to continue to some extent whenever you use the tractor, even if you resolve a venting problem. You only have access to the outside surface, so you can't sandwich the crack mechanically. If you just try to "weld" over it with heat, you'll want to remove the tank anyway. My advice is to just bite the bullet, order a new tank, and don't look back!

 

[rwork]

I'm going to give it a try to stop the leak. Price of replacement tank is $300 ! Ouch