Vented Fuel Cap - 06/21/17 05:35 PM
I ordered and received a new vented fuel cap from Chev of the 40's for my '37 Master Coupe (GB).
I needed to replace the non-vented aftermarket cap because it would allow fuel to splash out of the filler when the tank was fairly full and I made a left turn. I knew that if I added a gasket to seal that cap I would shut off the vent function and starve the fuel flow to the carburetor.
Now I am not sure if I have the right cap or perhaps there is a problem with the filler neck. The new cap is Chev of 40's part # 595857 which is the same part number that is listed in my 1940 parts catalog. Unfortunately there is also the possibility that the fuel cap was not made properly as I am experiencing with various reproduction parts.
The gas cap does not fit snugly on the filler neck. It seems very lose and feels like to could actually rotate off. So I added another layer of gasket material to it and it feels tighter. I am able to drive the car without any signs of fuel starvation so I think the vent is working properly. I have yet to fill the fuel tank completely to confirm if it will prevent the fuel splash-out.
Yesterday after I had driven the car for about a half hour I decided to check the fuel cap to see how it was fitting. When I released it there seemed to be pressure in the tank.
1) What can I do to make the cap fit tighter? Does anyone sell the rubber seal as a separate part?
2) Is the pressure build up normal? This means that the vent function is really a check valve and only allows air to enter the tank.
I needed to replace the non-vented aftermarket cap because it would allow fuel to splash out of the filler when the tank was fairly full and I made a left turn. I knew that if I added a gasket to seal that cap I would shut off the vent function and starve the fuel flow to the carburetor.
Now I am not sure if I have the right cap or perhaps there is a problem with the filler neck. The new cap is Chev of 40's part # 595857 which is the same part number that is listed in my 1940 parts catalog. Unfortunately there is also the possibility that the fuel cap was not made properly as I am experiencing with various reproduction parts.
The gas cap does not fit snugly on the filler neck. It seems very lose and feels like to could actually rotate off. So I added another layer of gasket material to it and it feels tighter. I am able to drive the car without any signs of fuel starvation so I think the vent is working properly. I have yet to fill the fuel tank completely to confirm if it will prevent the fuel splash-out.
Yesterday after I had driven the car for about a half hour I decided to check the fuel cap to see how it was fitting. When I released it there seemed to be pressure in the tank.
1) What can I do to make the cap fit tighter? Does anyone sell the rubber seal as a separate part?
2) Is the pressure build up normal? This means that the vent function is really a check valve and only allows air to enter the tank.