Tank pressurizing normal?

[halle09]

I replaced a bad sending unit and when i took off the gas cap(brand new) it was pressurized and hissed air out. Is this normal on these cars? 1973 cuda

[Strawdawg]

should be vented up front to the charcoal cannister.  Has that line been blocked off if someone removed the cannister?

[cudabob496]

get a gas cap that vents?

[roadman5312]

get a gas cap that vents?

                                            1970 cap, no canister.

[1 Wild R/T]

                                            1970 cap, no canister.

70 cap doesn't fit a 71, 72, 73 or 74.... The tabs that lock into the fill pipe are different...

[cudabob496]

If you have a gas cap that does not vent, why not drill a tiny hole in it.
The fuel cell in my trunk has a small vent that is always open, and seems
to work fine, and not cause any problems.

But actually, a slightly pressurized gas tank will help your fuel
pump work better.