[Texasbikers]

I noticed I have a lot of air pressure build up in my gas tank. When I take the cap off there is a large burst of air that comes out.

Is this a simple problem, as in my gas cap isn't venting properly and I need to replace it? Or is something else going on???

The worst part is, the pressure found a weak spot on my tank that was lined with the POR gas tank lining and now I have a leak to fix.

 

[Ggrahn]

Is this a simple problem, as in my gas cap isn't venting properly and I need to replace it? .

Nailed it right there. At least, that's where to start.

 

[randy chesnutt]

You got to get a vented gas cap. When you get one check it out. A friend of mine started his car and the engine went crazy and blew hole in his piston. He didn't know what caused the engine blew. He searched out everything and just checked the gas cap and when he removed it the pressure was so high it blew the cap off in his hand. The car was setting outside in the summer heat. The cap was not vented.

 

[FEandGoingBroke]

Some Vented gas caps vent inward not out...

Plus you should have a vent tube coming off your tank, shouldn't there be?

 

[galax-z]

63-4 don't have a vent tube. thats why the vented cap. it should have a pressure relief built into it

 

[puttster]

63-4 don't have a vent tube. thats why the vented cap. it should have a pressure relief built into it

Is there a vent for the tank on a 1965, or just the cap?

 

[Ggrahn]

66 tank does not have a vent tube, only a vented cap. They stock that cap at Autozone so getting one shouldn't be a problem. Locking even.

The only inlet/oulets on my tank at the return (former feed), the feed (sumped AN fitting) and the filler neck. I only added the sump.