Oil & Fuel Another diesel leak in my 5740's fuel tank

[Unclebuck257]

John,

That new steel tank is working out real fine for me. The only thing that I'm going to have to go back and do, additional to what I've done already, is to take some of that 3/8 inch black rubber matting I used for cushioning and sound control and put some of it on top of that thin part of the tank, at the rear of the tank, by the U joint. I have it lining the actual U joint itself already. As I stated in an earlier post, that part of the tank is held up by a big U joint that bolts on the top to the frame of the tractor. Since putting in the new steel tank, I've mowed about 100 pasture acres and I've noticed sound coming from under the tractor at about that point, and it sounds like the top of the metal tank hitting on the frame in the rough pasture areas. Once I do that, there won't be anymore sound at all. Otherwise, the steel tank is working out fine for me.

Ironically, my buddy who bought a 2006 5740C after borrowing mine a couple years ago, called me this weekend and he has the infamous "tank leak" too. Same problem, from the same source, and he lost 13 gallons of diesel in his stone and dirt driveway over it too. He called Montana and they offered to sell him a new tank, that supposedly had the problems eliminated from it for half cost, or approx $150.00, since his tractor is out of warranty too. It would still be hard plastic though and he's kind of like I am about that situation. Right now, he used epoxy to fix his old one temporarily and is making some other adjustments like eliminating the guard plates where they are now, etc. He's seriously looking at having a metal tank made for his too, in the longrun.

 

[Ron Blacic]

I also have a leaking problem with the poor design of the fuel tank.Montana knows they have a problem(will not admit to it).They sent me(I paid $182 for shipping) a replacement tank,do not see any design changes,there seems to be residue or future leak at the screw locations for the protector plates.only time will tell. I own the LS4950c

 

[FLHayman]

I have a 2006 5740C, bought used. After reading about the tank, I looked at mine, no leaks. But, the guard seemed to be attached to the problem area, so I took it off. I know, I know, it's a compromise solution, but it looks like a branch pushing against the tank or guard would have put some stress on it. Yes, more damage is likely on a direct hit without the guard.
Maybe there is something to be gained from enlarging the guard holes, (in case thermal expansion/contraction adds stress, too) and mounting the guards with nylon screws? It would break the guard off in a prying impact, but keep it on for a direct hit, the breaking nylon screws would possibly protect the threaded plastic recesses in the tank from bending too much.
Also, I'd love to hear more about the plastic welding that was mentioned earlier. I thought that it was tough to find compatible welding material, since the chemical makeup of different plastics varies a lot. Please post more about this, if possible.
Thanks to all.

 

[Unclebuck257]

FL,

The problems with removing the guard plate for me here where I live in Texas could be great. I live in an area known as The Barnett Shale with a lot of natural gas and oil. That also means shale rock, and a lot of it. Frankly, removing, and leaving off that guard plate is not an option for me with the rocks. That's why I never considered it.

I believe that the problem with those hard plastic tanks these tractors come with cannot be eliminated unless a person lives where the ground the tractor is used on is relatively smooth and even, because the stress that causes the tank to leak comes from just using it and the resulting vibrations.

I first repaired mine with very good plastic apoxy and that lasted about a year before I had the problem again, only much worse. I filled in the particular screw hole that was cracked and leaking, along with the crack out from the molded screw hole, and did NOT put a screw back in that hole at all. As I said though, a year, almost to the day later, I had severe leaking from another couple of screw hole areas. That's when I had a metal tank welded to the exact shape of the plastic one and then installed it on my 5740C.

You can get that apoxy at most auto and farm equipment stores. I forget the name of it though because my buddy already had some of it in his shop when we did those initial repairs. I remember it comes in its own siringe type dispenser too. I know he told me it was "high quality" and high dollar stuff too.

 

[jc7622]

Leaker here. I thought I was the only one, I gues not. I took off the guard and sealed it up.

 

[Amblansman]

Leaker here. I thought I was the only one, I gues not. I took off the guard and sealed it up.

And the same problem continues. This will be the first problem I've had with my 5740 that was not due to normal wear and tear since I bought it new in 2007. I will try the Permatex or Versachem fuel tank patches first, but plan on finding a fab shop to make me an aluminum replacement.

 

[cotman1]

I walked outside today and noticed mine dripping too, gonna look into a temporary fix (for now) and aluminum maybe as a replacement.

 

[Unclebuck257]

Cotman,

I wish you luck finding an aluminum replacement tank. Be sure and check to make sure ANY replacement tank you are looking at buying will fit into the area where your old tank is. That steel tank I had made in 2009 was made to the exact same shape as the old hard rubber one so it would fit into the tank area. It is still going strong and I haven't had any leaks since putting it in eight years ago. Good Luck and please let us know what you do and how it works out for you.

 

[cotman1]

I'm going to have it made, as there are no aluminum replacements that I know of.
For now, I'm ok, but only a matter of time before it lets go again.