tomstevens

I have been working on a 66 convertible for the last few months. Just got it to where I could drive it and notice a pool of gas under the rear. Fuel coming from around the sender in the bottom of tank. Ordered new o-ring and lock ring. Installed and it still leaked, but worse. Noticed the new lock ring was flatter then the original. No lip. Replaced the lock ring with the original and a tighter fit and no leak so far. Are the new lock rings meant for only a new style sender?

Tom

SonnyAK

I think the difference in flatness is probably just the crappy repro products out there now! Mine leaked too, until I went back and found an old thread that said you need to lube the seal w/Vaseline before install...I did that, and hasn't leaked a drop since!! Someone mentioned that the factory kept the seals in a bucket of the lubricant until they were ready to put them on...
Glad to hear yours sealed ok...

JohnZ

In the plant, we kept the fat rubber O-ring seals in a tray of motor oil for several hours before installing them; the requirement to do that is in the Assembly Manual, in the "Lubricants" section that decodes the lube symbol on the sheet that shows the installation.

SonnyAK

I remembered reading something about that, but couldn't remember the details...Thanks! Any preference on the best lubricant to use on one now when replacing it?

tomstevens

I thought it was just me. I think the reason it leaked in the first place was I had the back end jacked up for a couple of weeks working on the brakes. With low fuel it dried out. I could have probably soaked the old one in oil and reinstalled it. Been a mechanic for close to 50 years and am still learning.

Many Thanks ,

Tom

Blk63Vette

Here is Quanta gas tanks procedure

http://www.gastanks.com/63-67-Corvet...products/1947/

RK-TECT

My sending unit isn't leaking, but I see "seepage" around the perimeter of the lock ring (cam) and the raised lip where the cam fastens to the tank. When I wipe off the semi-dried gas, the color is black. I was told that gas won't turn black, so it is probably the rubber O-ring breaking down from the ethanol . My sending unit is only 5 years old, but I purchased a new one since it never read accurately (always a little lower than the actual fuel level). I hope the new O-ring is made of rubber that is ethanol resistant!

tomstevens

I have switched to non-ethanol fuel and carry some Lucus fuel additive on longer trips in case I have to use ethanol.