Fuel cap and tank venting
Here is the deal on "venting." ALL vapor system cars use what is commonly known as a "pressure vacuum" cap, which means it has RELIEFS in there to vent over-pressure, either pressure or vacuum. NO Mopar cap in the cars we talk about here uses a vented cap. Up until vapor control systems, they are vented through a tube connected to the filler pipe in the trunk. All the vapor controlled cars have a 1/4" vent line coming up front which ties in with the carbon can system. THIS IS your tank vent and must not be removed, plugged, etc
Caps are a PITA for these cars, as there are several, and they changed year by hear. Oldmanmopar or someone had a great illustration of the caps over the years..........
..........and here we go.......
Vented or non vented fuel cap?
Below is the cars BEFORE vapor control Evap controls started to happen in some 70 cars in CA, not sure if "all cars" in 71, but 72, later, all cars Federally had evap controls
Here is the deal on "venting." ALL vapor system cars use what is commonly known as a "pressure vacuum" cap, which means it has RELIEFS in there to vent over-pressure, either pressure or vacuum. NO Mopar cap in the cars we talk about here uses a vented cap. Up until vapor control systems, they are vented through a tube connected to the filler pipe in the trunk. All the vapor controlled cars have a 1/4" vent line coming up front which ties in with the carbon can system. THIS IS your tank vent and must not be removed, plugged, etc
Caps are a PITA for these cars, as there are several, and they changed year by hear. Oldmanmopar or someone had a great illustration of the caps over the years..........
..........and here we go.......
Vented or non vented fuel cap?
Below is the cars BEFORE vapor control Evap controls started to happen in some 70 cars in CA, not sure if "all cars" in 71, but 72, later, all cars Federally had evap controls