1971 challenger gas tank

[mopar440]

  Hey guys not sure where to post this, when i fill up my car seems like it whooshes out a lot more air when i take the cap off then it used to, is this normal ,or should ther be no pressure at all ? do i need to do something with those goofy hose set ups in the back. put a new gas cap on, same thing !

[wagesofsin]

i thought the early tanks didnt have the hoses like the later ones to the vapor seperator.   
regardless, it must not be venting.
make sure all the hoses are unobstructed.

[Moparal]

my 70 has those ecs hoses and it is all hooked up correct. So if it is full or low on fuel it has no pressure issues. 

[Chryco Psycho]

you should have a vent line up to the valve cover breather , , it should not be blocked anywhere between the tank & valve cover

[mopar440]

  thanks for info on tank , was going to start taking apart,  will check that, thanks again !

[daveh]

Anyone have a diagram of the line that is to go up to the valve cover?

[71 DEPUTY]

it uses a 3 port breather cap- see attachment.

[daveh]

Awesome thanks