fuel leaking from fuel filler

I've noticed when the tank is full on my cj-8, gas spills back out of the
filler when I'm driving (bumpy roads, etc), even though the gas cap is on.

Is that sheet metal flap inside of the filler supposed to prevent this?
Mine doesn't seem like it seals, but I'm not sure if it is supposed to.

The flapper valve is designed to keep the gasoline from blowing all
over the Darwin candidate releasing the gas cap too fast. You need a new
cap. Maybe, make sure your charcoal canister and vapor system is working
correctly: http://home.sprynet.com/~dale02/evaporat.htm
God Bless America, ßill O|||||||O
http://www.billhughes.com/

Jeff Scherb wrote:
>
> I've noticed when the tank is full on my cj-8, gas spills back out of the
> filler when I'm driving (bumpy roads, etc), even though the gas cap is on.
>
> Is that sheet metal flap inside of the filler supposed to prevent this?
> Mine doesn't seem like it seals, but I'm not sure if it is supposed to.

Replace the cap, it is dead.

The cap has a seal in it and doesn't splash leak. It even has to pass
the emissions test for not leaking up to a certain pressure on my CJ7.

Caps are cheap at least. The chrome Laredo cap on mine is a basic
generic gas cap that most parts stores have on the shelf.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

Jeff Scherb wrote:
>
> I've noticed when the tank is full on my cj-8, gas spills back out of the
> filler when I'm driving (bumpy roads, etc), even though the gas cap is on.
>
> Is that sheet metal flap inside of the filler supposed to prevent this?
> Mine doesn't seem like it seals, but I'm not sure if it is supposed to.