I have a YJ 93 that when I fill up the gas tank, the gas will spill out of the gas cap. Until about 3/4 tank and then it doesn't. That is after fill up, and driving, the sloshing of the gas in the tank will send the gas back up the filler tube, filler neck and out the gas cap.
My question is if I am missing a one way valve on the filler neck. On the filler neck (which is a bit rusty) on mine there is no flap.
I have purchased a new gas cap, but this did not solve the problem. I was thinking the cap was not sealing. Now I am wondering if I need a new filler neck.
I am wondering what I need to do to prevent the gas from spilling out the filler and gas cap.
Thanks for any ideas.