fuel system

[bonjo]

is the fuel tank/ system pressurised or sealed?

when I open the fuel cap I hear gas escaping (more so if the tank is low on fuel).

If so does this mean that with the cap closed, then no outside air / moisture gets into the tank (until next opened of course)?

 

[yossarian247]

3 hours ago, bonjo said:

is the fuel tank/ system pressurised or sealed?

when I open the fuel cap I hear gas escaping (more so if the tank is low on fuel).

If so does this mean that with the cap closed, then no outside air / moisture gets into the tank (until next opened of course)?

 

It should be under a slight vacuum, rather than pressure. When you open the cap it will be sucking air in. This negative pressure is normal, its to help prevent petrol fumes escaping from the tank.

[bonjo]

yes what you said makes more sense. thanks

[daveh_rav4]

I think your confusing that sucking sound when you release the fuel cap... in my case its the sound coming from my wallet as the bank notes are being extracted to pay for the fuel!