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Fuel tank pressure
Posted: Wed Jul 12, 2006 6:47 pm
by brighty
Is a fuel tank meant to have a positive, or negative pressure when the fuel cap is opened.
eg, is it meant to let air out.... or suck air in????
Posted: Wed Jul 12, 2006 7:11 pm
by -Scott-
I always thought fuel tanks breathe through the vehilce's carbon cannister.
But some tanks definitely generate a pressure differential, so FIIK!
Scott
Posted: Wed Jul 12, 2006 7:15 pm
by simkell
there shouldn't be a vacume if any thing a slight amount of pressure.
if there is vacume it will affect a mechanical pump in providing enough fuel to either diesel pump or petrol carby.
Posted: Wed Jul 12, 2006 7:49 pm
by V8 Middy
What Scott said... modern vehicles have a vent pipe into a charcoal canister which then has a vacuum lne into the intake manifold so really there should be no pressure or vacuum when u take the cap off.
My tank heats up and pressurizes when I run on LPG but I'm yet to figure out why but thats another story...