Please help info needed 67 dart gas cap!

[LovetheA's]

Here is the situation I have a 67 dart that I believe had the gas tank replaced with an original factory setup. I want to replace/upgrade the gas cap that was with the car. Old chrome cap has some pitting. The problem is the correct cap when researched shows a "non pressure release" cap. The cap that was with the car when I bought it I believe is a pressure release cap due to the raised up dome in the center on the backside of cap. The correct cap shows no center dome on backside. What do I look for on filler neck or tank to make sure tank is properly vented if I put non pressure release cap on?

Carl

 

[72bluNblu]

The later tanks weren't vented at the cap, they had another vent off of the tank, so I don't think there's really anything to look for at the filler neck. The later tanks had different set ups, but involved additional lines run either off the front or side of the tank that vented it, some to a charcoal canister in the front of the engine bay.

Not sure this will help either, but at least it shows the type of cap you're looking for...

 

[furyus2]

My 69 Dart has a 1/4 " tube that starts at the top of the filler tube and goes down to the filler tube floor seal, and vents to the outside next to the gas tank.

 

[72bluNblu]

My 69 Dart has a 1/4 " tube that starts at the top of the filler tube and goes down to the filler tube floor seal, and vents to the outside next to the gas tank.

Interesting. All of mine are vented off of the tank, nothing out to the filler neck. But then mine are all 71+.

 

[LovetheA's]

Thanks everyone for the replies. I guess the question I have now is am I ok to use a cap without pressure release. I hear horror stories about the gas tank collapsing or expanding due to pressure issues. From what I am gathering even in my 67 dart there was a way that the tank was vented to release the pressure. If so where would it be on my tank?

Carl

 

[doug 371]

its on the filler tube as stated above

 

[DDodger]

Thanks everyone for the replies. I guess the question I have now is am I ok to use a cap without pressure release. I hear horror stories about the gas tank collapsing or expanding due to pressure issues. From what I am gathering even in my 67 dart there was a way that the tank was vented to release the pressure. If so where would it be on my tank?

Carl

some 70 cars and everything 69 and earlier had unvented caps, no pressure relief, no nothing. completely sealed. as above vent line came off the filler neck. look in your trunk, feel your hand up high on th efiller tube