Fuel Shut-off O-Ring

spinelll

spinelll

Senior Member
After I replaced my fuel shut-off, I thought I might play with the old, leaky one. A buddy of mine will help me "lap" the brass sections. However, I'd also like to get a new O-Ring for the stem but can't find the right size. I tried the local hardware store but was not successful. I know that these parts are sometimes very specific but does anyone know the correct dimensions?


Thanks
Leo
 

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My small hardware store has bins of different size o-rings, you should find a different store if they don't have your size.
 
From memory, they don't have an O ring in there unless maybe, that valve itself is an aftermarket replacement. The originals had a ring of some crushable material that was compressed by a nut on top of it. Snyders has them https://www.snydersantiqueauto.com/product.htm?pid=979344&cat=41707

If your car is a driver and appearances are not so important (who looks up there under the fuel tank anyway), I suggest using a 1/4" ball valve available from any plumbing supply. NO leaks and durable.
Alternatively, they have this repair kit, which I have used quite successfully.
https://www.snydersantiqueauto.com/product.htm?pid=979345&cat=41707
 
That looks like a late 31 firewall shut off gas valve, originally they have a packing that’s made of graphite ? Your on the east coast call Snyders or Bratton’s for the proper seal
 
The kit Synchro refers to will not fit repro valves, only for original.

You might want to ensure the "o" Rings from the hardware store are gas/alcohol resistant?
 
I have used waxed string for that type of crush packing and it works great. I think I would use soaped string with gasoline.
 
Several years ago (maybe still) there were repro valves on the market that used o-rings rather than packing. This is probably one of them. Keep searching for the correct o-ring. If not available at a hardware store or plumbing supply, industrial supply house is best bet. And,yes, make sure it’s gasoline resistant.

By the way, when the valves are apart, the piece shown in the picture looks the same whether it’s a late 31 valve or 29 - early 31 valve.
 
Make sure you use a little EZ-Turn on the valve when you assemble it.

McMaster-Carr has a wide variety of O rings for different usages. The O rings are flexible so an exact replacement is not necessary. Measure the diameter of the rubber and the ID of the ring. McMaster-Carr has metric sizes too so there is bound to be a match. Calipers are handy to measure the size.

https://www.aircraftspruce.com/catalog/cspages/ezturnlube.php
https://www.mcmaster.com/
 
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Thanks for all the replies.
It's a repro valve. No packing.
Used on a 1930, under the tank.

The hardware store did have bins of O-rings but none matched.I'll try another store.
My general experience with any o-ring is if you don't get the exact match, they fail quickly or don't work at all.
 
Nitrile butediene o-rings will last for a while. Viton will last longer. Kits are available with different sizes.

I use aircraft o-rings since I have charts for the part numbers. Fluorocarbon (Viton) and fluorosilicone are the best o-rings for fuels. They work well with gasoline, jet A, or jet B fuel. Plus any kind of lubricating oil. Life is unlimited as long as they are in their original package.
 
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