I filled up my gas tank this weekend. A few hours later in the hot sun, the gas was flowing out of the filler neck (with cap on). Obviously it had built up vapors inside and was pushing the gas out.

Now at first I thought I had filled too full. I siphoned it out of the filler neck. Next day it did it again though not as bad.

Any ideas on the cause? Did I simply fill too full or is there a problem with the vapor line?


1951 Chevy 3100 w/235