MTFCA Forum

The fuel valve on my 27 Roadster has gotten impossible to turn off or on. Before I installed it about 4 years ago I lapped the brass valve with lapping compound and it’s worked great, easily turned and no leaks. Well I still have no leaks but it’s very stiff. Will it need to be lapped every so often to keep it operating?

Just back off on the valve pack nut a little bit so you can turn the valve. Be sure you have a a quart plastic container underneath to catch leakage you may have while the pack nut is loose.

Moxie26 wrote: ↑

Tue Jul 02, 2024 8:15 pm

Just back off on the valve pack nut a little bit so you can turn the valve.

I did that and it didn’t help, I didn’t have it really tight to begin with. The only thing that did help was once I backed off the packing nut I pulled out on the valve and it would then turn but once I put the nut back on and barely tightened the nut, just enough to keep it falling off it locks up again.

May have to take the valve apart. Rotate some crocus cloth inside the cast iron housing for the valve. Do the same on the valve surface of the brass valve itself. Rinse with solvent of your choice . Polish to make smooth, then reassemble with a schmeere of anti-seize and a new lead gasket.

Have you tried Timesaver? the aircraft industry has BASO & EZTURN gas valve grease made just for this but have a firm grip on your wallet.
Craig.

Langs sells a valve lube that worked for me. I used Timesaver first.

I used Timesaver when I first polished the valve.

If lapping the valve worked before, take it apart and lap it whenever it binds up, but only enough to clean off the buildup and apply a dab of grease to the valve when assembling. Jim Patrick

Craig Leach wrote: ↑

Tue Jul 02, 2024 8:33 pm

Have you tried Timesaver? the aircraft industry has BASO & EZTURN gas valve grease made just for this but have a firm grip on your wallet.
Craig.

This works very well. No seizing, and turns well. No leaks.

I have found that our modern fuels tend to get thick like varnish when they get a few months old. I have even had the choke valve on the carburetor stick. At first I wondered why the car would not start when cold, and ran rough when warm? The choke was neither closing completely nor opening fully. so I cleaned it up and it works fine and runs smoothly. Sometimes it can even clog the jets and passages in the carburetor or plug the fuel line. The same thing can happen to the fuel valve when you don't use the car often. So after you get it cleaned up, open it and close it more often even if you don't drive the car every day. A little bit of bar soap makes a good lubricant. problem with grease is that it is soluble with gas.
Norm

I use non ethanol gas 95% of the time, I thought that would reduce the buildup of varnish. I’ll remove the valve and clean/lap it.

There’s a lube for gasoline petcocks that fixes both leaks and tight turning. It only comes in 1 oz. tubes so a tube will last your club a lifetime.

Only the California prescribed formula gas is available here. There is Summer blend and winter blend.
Norm