Fuel tank sender leak

[Carl Froehlich]

This weekend I helped a builder fix his leaking fuel tanks. Both tanks were leaking from the fuel sender. The tanks are 13+ years old and have never before leaked.

The fuel had turned the pro-seal to goo at the leak (both senders had a good amount of proseal covering them). The good news is I was able to get most of the proseal off with just a small chisel. The screws came right out with a 90 degree drive. Pulling the sender I found the orginal rubber gasket with no proseal on it. This made prep for resealing easy enough as the mating surfaces were perfectly clean. The rubber gasket went in the trash, some proseal on the tank and sender, new screws, a multimeter check to make sure the sender was grounded, then a few brush strokes of proseal over the screw heads and around the sender edge for good measure and all is well.

The cause of the leak was obvious but I was amazed that this simple rubber gasket lasted as long as it did. While I know the normal practice is to never use this gasket, I tend to build using the gasket but I put proseal on both sides, on the sender and on the tank. My thought has been that if I ever do need to replace a sender cutting the gasket with a razor will make life easier.

On my builds I also add a ground wire under one of the sender screw heads - I don?t trust aircraft grounds.

One other observation - it was much easier than I anticipated to pull and replace the sender with the wings on.

Carl

[Plummit]

Was this on a -10?

-Marc

[Raymo]

Recently assisted an owner with his 20 year old -6 right tank. The original cork gasket was in place so the sender came off easily. Appeared to be leaking from the screws.

Just proseal during reinstall, lightly tightened. Fully tightened after the proseal set up the next day.

[rv7charlie]

I've had good luck with this stuff:

https://www.permatex.com/products/ga...lange-sealant/