The Stovebolt Site Forums The Shop Area General Truck Talk Vented Gas Cap, am I crazy?

So, I replaced my old dented gas cap, with a locking vented cap. I drove all of two miles to the gas station, where I jumped out of the cab, put in the key, only to have one of the latches come off the cap, into the tank. Dang newfangled gas cap. So, I bought a vented plain jane chrome cap. I drive to the gas station, fill the truck. Drive home, park in the sun. Truck heats up. Pressure builds in full gas tank, and starts to leak up out of the screws surrounding the tank sending unit. I figure I'm going to go for a drive, open the door. Decide to wait for a while, what with the gas coming out of the top, and running all over the cab floor. I open up the vented cap,and get the psfffft! sound of pressure. Now, I put the gas cap up to my mouth, you can suck air though the vent, but not blow out. Is this normal for a vented cap? Or did I get yet another dud? Seems to me that there should be an avenue for the inevitable pressure to escape.
Christopher

They are supposed to be like a check valve. They allow air to come in to replace the fuel as you use it. But in case you lay the vehicle on it's side, gas is not supposed to run out. I don't think they came that way. I seem to remember a time when the original could be traded for a safe vented cap. I think all vented caps are now like a check valve by law.

you'll probably be better off if you don't fill all the way up to the top of the filler neck to allow room for expansion, this applies to all the new cars as well since they are not vented at all, fumes are stored in the charcoal canister and burned later while driving, overfilling causes the canister to become saturated with raw fuel instead of fumes. causes variety of performance problems and check engine lights to come on.

Just drill a hole through the thing. I'll be damned if I'd have raw gas leaking out into the cab of my truck just to keep gas fumes from leaking into the atmosphere while China is building two coal fired power plants every week.

Have we all lost our minds?

"Have we all lost our minds?"

You have, if you think that someone is forcing you to buy a certain style of gas cap.

Christopher, just get a readily available original style gas cap. Even locking gas caps are available in two styles.

Vented or not, gasoline will expand when it warms up - you should not fill the tank into the filler tube.

I always drill a small hole in them when I use one on a tank with no other vent.

If I live to be 100 I'll never understand why people have to be so nasty. I was responding to crenwelge when he posted:
But instead of just correcting HIM you have to insult me.

And coming from you? I'm disappointed... I thought you had more class.

Gentlemen, Gentlemen! easy, it's just a ol gas cap and not worth a dual.
dg

This cap is a re-pop, but from our local supplier, as I don't really need to ship every little thing from the States up here. I was going to just drill a little hole in the venting mechanism. - My never ending struggle against the man.
Christopher.

I do two things to fix this problem;

#1 Fill up on the way out, not the way home.
#2 Always park with the cap uphill.

Jeff

Ahhh Woody, your mudder wears combat boots!!!

Now that's an insult!!!

Ol' Deadass