# 915B Zero Turn Mower Leaking Gas Tank



## Frank Brogan (Jul 22, 2020)

Does anyone have any experience or recommendations on how I can fix a leaking gas tank on my zero turn mower? I cut a one inch long slit in the side of the tank when I was mowing too close to an object. New tank is $1,000 or so. There must be some way to seal up this slit.


----------



## Toolsteel (Aug 1, 2019)

What material is the tank made of? Can post up a picture of the damage?


----------



## Frank Brogan (Jul 22, 2020)

It is some sort of plastic that John Deere uses. I left the ranch without taking a picture. Will post one later this week. Thanks for your post


----------



## wjjones (May 28, 2010)

Buy a new tank, or a good used one.


----------



## wjjones (May 28, 2010)

I hope you can patch it but I have never seen, or found anything that works. The new tanks are pretty pricey to I bet.


----------



## Longhorn294 (Oct 13, 2019)

Frank Brogan said:


> Does anyone have any experience or recommendations on how I can fix a leaking gas tank on my zero turn mower? I cut a one inch long slit in the side of the tank when I was mowing too close to an object. New tank is $1,000 or so. There must be some way to seal up this slit.


I would look into places that repair plastic bumpers. They basically weld the plastic with heat, like a soldering iron basically. Worth a try at the price of a new one or alot of looking for a used one...


----------



## Bob Driver (Nov 1, 2017)

Yep... The first time I saw the fuel tank set up on a 915B, I thought the Bright Idea Fairy had once again visited the John Deere Engineering Department. I have often suspected "The Fairy" actually has a second a second home there. I wonder why they even bothered with that little piece of logo trim on the side. My first thought was they should have just installed a big bullseye decal, especially with the tank mounted on the left side of the machine with no protection.

Never had much luck with epoxy, but they've gotten much better over the last few years. Repaired a lot of broken ATV plastic using a cheap Harbor Freight "Plastic Welding Kit". The one that is basically a pencil soldering gun, but it takes a lot of practice to get it right. Then of course, there's the gas vapor issue with a fuel tank. 

Grandpa always told me "You got to be smarter than what you're working on".... I'd sure as hell try to come up with something to out smart a 1" slit in a plastic tank, before I paid $1,000 for a new replacement.


----------



## Hacke (Feb 22, 2011)

If you plan to weld, you need to find out what type of plastic you have in order to get the proper rods for it. Look for recycling symbols and text. In this pdf you will find some good information:
https://www.polyvance.com/thebook.pdf

As in all welding, it is important to have the correct temperature in the "puddle" and I have never made a decent plastic weld. I tried Fiberflex from Polyvance (former Urethane Supply), and I was pretty satisfied with it. It is somewhat like hot glue and works on most thermoplastic types. That was the main reason for trying it, because plastic parts on cars often have strange TPO/TPE designations which you can not find an exact rod for. Some parts does not have any useful information. With Fiberflex, you do not need to care about melting temperatures, just smear it out when it gets soft, and you can go back and work it however you like.

Here is a video showing the steps:
https://www.polyvance.com/video/fiberflex/fiberflex-bumper-repair

I only buy the sticks. I have found that a stainless mesh with finer mesh than in the video is easier to work with. You can get cheap mesh from kitchen strainers (sieves?). I use an old type soldering iron, where you attach the tip with a screw, like this:
http://img.banggood.com/thumb/water...4/F7/2abaa72c-8fe4-4ca9-8b82-d6daa2cddafb.jpg
I flattened a piece of copper pipe to make a "spatula" and inserted into the iron. Clean the surface before and after grinding with acetone (at least on PE), isopropyl alcohol (rubbing alcohol) or brake cleaner.

I have not done a gas tank, but since you cannot reach the inside, you have to put the mesh on the outside. That calls for grinding/sanding a ditch deep enough to make room for the mesh and Fiberflex so it looks nice when the repair is done.
One thing to have in mind is that when you heat the mesh to sink it into the material, the mesh stores a lot of heat and that can make the plastic soft over a larger area than you think. When you push on the mesh, the plastic can stretch and bulge inwards. To avoid that, you can pause the "meshing" now and then in order to let the plastic cool down. Perhaps it is possible to support the backside of the tank with a piece of wood through the filler opening.

By the way, if someone thinks of doing a Fiberflex repair on a fuel tank, contact Polyvance and ask if the material is resistant to the fuel. I have not found any information about that.


----------

