Join Date: Mar 2010
Location: Palos Hills Illinois
Larry, I agree. The factory chassis repair manual says hardtops, sedans and converts have nonvented caps. Station wagons have a vented cap, because they fill from the side, not behind the rear license. If I put a vented cap on, I expect gas to leak out the cap under full tank acceleration times. My vent tube and tank are new and clean so I know it's not clogged. It is 85-90 (and miserable) here in Illinois so maybe it's temperature related. I don't think there is much I can do, other than open the cap often to let air in, if that's what the tank is looking for. I still don't understand why the vent tube doesn't provide full ventilation though, whether expanding or contracting of the fuel is occuring. That's why I think it has an internal flap, to only allow air 'out'.