Leaking 1939 Left Hand Gas Tank Valve

[Steve Little]

Hi. After lightly lapping the peg into the body, "fine lapping paste" clean it and wet lap the steel peg into the brass body with CRC.
Have a look at the bore and you might see a smooth line in the very bottom of the bore.
About 1/16" from the bottom of the bore.
It is a worn in step in the bore. The peg will sit on top of this step and never lap a seal until you get rid of this step.
Increasing spring pressure by stretching or adding washers will not effect it.

[Highlander]

Checkout Matt Olsen's blog www.oldbikesinsd.blogspot.com Sunday Fed 12, as they are working on a solution to this problem.

[ricmoran]

Thanks Steve & Highlander for your replies. I've seen the "o"ringed insert some where else before, I think Chris Haynes mentioned something about the too.

I discovered that who ever assembled the bike I have did something pretty dumb, they used what looks like JB weld with the petcock to tank fit to stop what could have been a major leak.

One of those penalties one pays when buying something that one wa snot aware of who did the work and how good or bad they were in doing the work.

The material is grey and is very hard that was used. I think it is JB weld.

It takes better than 600 degrees to liquify the JB weld, thus that would ruin the tanks paint job as well as perhpas some other unwanted results too.

So with that the RTV is in process of cure and if that does not cure the ills, the next step is the "O" ring.

Steve pointed out the wear groove, and yes about a 1/16" in form the small taper side on the brass body, you can see the wear groove.