Do our tanks rely on a pressurized environment? Or will the pump function normally without that situation?

 

Fuel tanks should not be pressurised. There's a valve by the fuel tank that stops excessive pressure or vauum from building. The pump does not need any assistance to work.

 

Thanks for the info, i was just curious..

 

the pressure will however build up if you cap off the line that leads to the charcoal box. The other option, and works just as well is to leave the line uncapped and atm pressure it. In theory... your gas might all evaporate though :P I don't believe the pump has an issue with pumping in the pressurized state. (actually vacuum)

 

So...when I went and got the fuel tank filled up yesterday, and took the fuel cap off and hear a whooshing sound (I'm not sure if it was pressure or vacuum).....then I should take some time off to check out the fuel tank check/cut valve?????

 

The check-and-cut valve opens when the vacuum reaches a certain threshold. It's a spring-diaphragm setup.

So, it would be normal to have some residual vacuum when you fill up the tank.

Same thing with pressure.

Hugues -

 

The check-and-cut valve opens when there's approximately 1psi of pressure or vacuum. You don't need much pressure or vacuum to get the whooshing sound.

 

Hey guys, it seems that my car has way over 1 psi of pressure built up in the tank. I left the line uncapped, but when I open the cap, it feels like there is a LOT of air coming out. Way more than I'm comfortable with.

Recently, I had the tank cleaned and sealed.... the guy who did the work told me that he took the check valve on top out, however I wonder if it got clogged somehow, and wont let the pressure escape?

I'm afraid of driving my car right now.