vented gas cap for 57 Plymouth?

[Rusty Muffler]

I assumed I needed a vented gas cap and got a new one that's "supposed" to keep in vapors. When I unscrew it I hear air like a bottle cap off a carbonated drink. I read a negative feedback that this cap sprayed someone with gas when removing. Doesn't sound very vented to me? Do they make an identical old type gas cap these days or shall I drill a small hole in mine? Thanks!

 

[58Belvedere]

RE: {Chrysler 300} Re: 1957 gas cap and tank venting .
Hi , I think you have that backwards— 57 requires vented cap , on dodge at least . Someone had put a non vented , on mine , way back in 1960 . It “ ran out of gAs” or “ frozen gas lines” —-all this bs ( hey it always started up after heating lines or new gas) . Caused by a vacuum in tank ! Which slowly fades out as you fix — anything!

I found out doing “ stuff “ in the woods ( Bob Segar) one winter night idling a long time , all of sudden Big Bang behind car, I jump out thought someone out there hit the trunk lid . Kind of scared !!I go to drive away car stalls = Yow !
By then I had gas in can in trunk over this stupid repetitive problem and no $ to fix it anyway .
So I get the gas , open gas filler , huge whoosh inwards but also big bang , as gas tank snapped back out . Aha
So yes , no gas tank vent on car in 57 , only .060 hole in cap .
The internal or external pipe you see on gas fill neck only vents air back into top of gas filler pipe as you fill tank , has nothing to do with this overall tank air vent ( and also does not work well (!) —thus the big spill out all the time with auto fill ) .
Jg

 

[58Belvedere]

https://www.oreillyauto.com/detail/...4/automotive-car-1957-chrysler-saratoga?pos=0

 

[58Belvedere]

MotoRad Gas Cap for 1957-1961 Plymouth Suburban

 

[Rusty Muffler]

RE: {Chrysler 300} Re: 1957 gas cap and tank venting .
Hi , I think you have that backwards— 57 requires vented cap , on dodge at least . Someone had put a non vented , on mine , way back in 1960 . It “ ran out of gAs” or “ frozen gas lines” —-all this bs ( hey it always started up after heating lines or new gas) . Caused by a vacuum in tank ! Which slowly fades out as you fix — anything!

I found out doing “ stuff “ in the woods ( Bob Segar) one winter night idling a long time , all of sudden Big Bang behind car, I jump out thought someone out there hit the trunk lid . Kind of scared !!I go to drive away car stalls = Yow !
By then I had gas in can in trunk over this stupid repetitive problem and no $ to fix it anyway .
So I get the gas , open gas filler , huge whoosh inwards but also big bang , as gas tank snapped back out . Aha
So yes , no gas tank vent on car in 57 , only .060 hole in cap .
The internal or external pipe you see on gas fill neck only vents air back into top of gas filler pipe as you fill tank , has nothing to do with this overall tank air vent ( and also does not work well (!) —thus the big spill out all the time with auto fill ) .
Jg

Yes 58 and thank you. To be clear this "new" cap claimed to be vented.

MotoRad MGC-46 Fuel Cap https://www.amazon.com/dp/B000C5GAIY?psc=1&ref=ppx_yo2ov_dt_b_product_details​

 

[Rusty Muffler]

MotoRad Gas Cap for 1957-1961 Plymouth Suburban

This looks like the same thing and description but they seem to be hiding the part #.

 

[Rusty Muffler]

This looks like the same thing and description but they seem to be hiding the part #.

I think this has to do with going green. I don't like the sound of pressure in the tank. I feel more comfortable with drilling a hole.