gas cap vented?

[lt704]

Hi Folks....Just a quick question. My 68 has the gas tank behind the seat. My tank has no vent, just the filler tube. My question is it normal for me to smell gas outside the cab from the outside vented gas cap. This is the only place i ever smell gas. Thanks for the imput. Russ.

[68gmsee]

A few things to mention. First the cap has a built in vent feature that allows pressure to escape when it reaches a certain psi (don't remember what it is).

Second, the fumes smell is normal when the cap is venting -that is the temp has risen and the gas fumes psi exceed the allowed limit.

Third, do not overfill these tanks. This can cause some spillage or seepage that will make the problems worse.

Now another thing I will mention is that I had a similar problems with fuel smell all of the time. New cap didn't help and I finally got a new tank from Spectra and all of my fume smell problems are gone. Turns out my old tank had tiny micro holes on the bottom that allowed enough gas to smell but not to accumulate on the floor board. Basically the gas would evaporate as it seeped out.

[lt704]

Thanks for all the valuable information 68GMSEE. It helped alot...Russ

[Sammy]

68GMSEE is right. Also if anyone has messed with the fuel sending unit they could have it slightly off centered also or the O-Ring could be dry rotted after all these years. If you get bored might not be a bad idea to pull the seat and have a look.