I'm looking to put a locking chrome gas cap on my 68 F100. I've seen one on ebay that claims to be vented but everywhere else I look they specifically say 'unvented'
When I fill up my truck and its a hot day, gas squirts out. Is that becasue my current cap is vented or unvented?
2007-08-15 05:59:01 · 3 answers · asked by Spudboy 1 in Cars & Transportation ➔ Maintenance & Repairs
A 1968 F-100 uses a vented cap, to prevent pressure from building in the tank when the gas expands on a hot day. It also allows air into the tank to take the space of fuel you are using!
Newer vehicles have sealed (un-vented) systems with vapor recovery, but your truck was built before those smog control devices were used!
2007-08-15 06:24:32 · answer #1 · answered by fire4511 7 · 3⤊ 0⤋
Unless you installed a sophisticated injection system in your 68 F100, I think you will need a vented cap.
The unvented cap is used in the fuel systems that have a gas fumes recirculation system. These cars have a canister in the engine compartment connected to the fuel rail and to the gas tank.
2007-08-15 13:21:18 · answer #2 · answered by Wrenchmeister 3 · 3⤊ 0⤋
The vented gas cap allows pressure to be relieved thus allowing you to take the cap off without blowing up in your face.
2007-08-15 13:04:28 · answer #3 · answered by steve h 2 · 0⤊ 2⤋