Fuel Sending Unit Leaking

[Gene M.]

My AC fuel sending unit (made in USA) started leaking the other day. Leak was thru the two studs that attach the harness leads. The big "O" ring that seals the assembly to the tank was fine. After removal I discovered the square cross section rubber ring around the studs was the issue. Appears this is a special seal. Parts stores do not have anything like it. A standard "O" ring is round cross section and don't work. This seals against the threads and the sheet metal housing. Compression by the nut enables the seal. I replaced these seals with a grommet type that has a groove to trap the sheet metal and fit tight with the threads. To enhance seal I used #2 permatex in groove and against threads. The assembly appears to seal up well I will post back later, soon as weather is nice to refuel outside. That should give the permatex a good month to set up (north east). The proof is if it leaks or not.

Anybody go thru this type leaking problem and have a fix that worked?

[Michael M.]

Re: Fuel Sending Unit Leaking

Gene, first things first. Great job in Kissimmee. For your sending unit this is the only area I have had problems with leaks. One fix is to lightly tighten the nuts. I had a sending unit restored by John Wolff and after getting it back and installing the unit it was leaking from the spot you mentioned. After a phone call John said after he restores the units they never leak from that area. I sent the unit back and all John did to fix the leak was to gob more sealant maybe (permatex #2) on the inside of the sending unit. Johns stuff is white in color so far no more leak. Sounds like your on the right track. Good luck Gene and thanks for your time in Kissimmee.