Gas cap

[aa010175]

What venting gas cap is to be installed in a 62 car? Vented or non vented? Thanks Dave

[Karl]

G'day.
I own a 63 so there may be some differences.

When I purchased my car it had a vent pipe as original which wrapped around the tank spout and a non vented cap.
On some drives especially on winding roads up an incline and it would depend on how full the tank was I could smell petrol. It was so bad once that I thought I had a bad leak so I stopped and couldn't find any leaks.
Once I parked the car facing downhill and the tank was full, the weather was hot and fuel started to dribble out of the vent pipe because the fuel was heating and expanding in the tank.
I believe the vent pipe goes into the tank and to the front of the tank - I could be wrong on this but this is the only explanation I have for why the fuel would come out.

I an attempt to fix the problem I blocked of the vent pipe and fitted a vented fuel cap. I haven't had a problem with smelling fuel. However now when the tank is low or nearly empty and I undo the cap to fill the tank there is pressure in the tank and you can hear it rush out. This has never been a problem, at least I know there is no leaks or holes in the tank.

Keep in mind that a vented cap is a one way valve to let air in as the fuel is taken out. If you don't let the air in a low pressure will form in the tank as the fuel is taken out and it will come to the stage where the pump will not be able to draw fuel out of the tank and the engine will stop.

Karl.

[Ducksface]

My lancia used to pressurize the gas tank. It was never a problem.
I have a 7-63(? I'll double check)date coded, correct locking cap, nos, in its original box.
If research tells you that this is a cure, let me know and I'll swap you something for it.