I have a 70 Challenger(non ECS) with a 440 six-pack that has just been through a rotiserie resto. After starting the car and running it up and down the driveway a few times I noticed a steady noise coming from the fuel cap. I removed the fuel cap and it relieved alot of pressure. The noise is apparently coming from pressure leaking through the cap seal. I tried to blow through the cap, but could not (yes, it is a "vented"cap). I drilled a small hole in the plastic check valve and could then blow through it.
Problem solved , right?
On my maiden voyage accross town to attend a car show I arrived and all was quiet, but there was now a couple "brownish" fluid stains from the gas cap to the wheel well that I could not wipe off. Obviously gas decided to leak out of the cap and mix with what I think is sound deadner material and then streak my new PPG Clearcoat.
Every thing is new on the car, gas tank, fuel lines vapor seperator.
Did I just have a bad vented cap? Is there something else I can be overlooking. Why is there so much pressure in the tank?
Any help would be appreciated.