My 70 Mav (non-emissions) gas tank is not releasing pressure. Last weekend when it was nice outside I had the garage doors open so the sun was hitting the back of the car. I smelled gasolins fumes and noticed that gas was bubbling out of the rubber fuel line in the engime compartment (not hooked up to the fuel pump, open end plugged). I loosened the cap and a huge amount of built up pressure was released (gas gushed out as the pressure bled off). Figured I must have overfilled the tank, so I drained out about 10 gallons, but the next day it did the very same thing. This is not a CA car with the emissions stuff, so I know the gas cap is supposed to be vented. It doesn't seem to be allowing built up pressure to release into the atmosphere. If memory serves, vented caps have a hold in the middle and I believe there is some kind of spring loaded pop-off valve inside to release pressure. There is no such hole in this cap. I'm pretty sure it is the stock deluxe/LDO cap. Any ideas? Thanks.
Tom, I have had this problem in the past too. My 76 Stallion has done this to me twice, and I had to repaint the tailight panel both times. I finally bought another gas cap, same as the one I always had and it hasnt done it since. But I never top the tank off anymore, so who knows if it is corrected anymore. Still remains one of life's great mysteries to me. Dan
