Fuel tank pressurised?

[davetherave]

Are s13 fuel tanks pressurised? As mine is leaking from the top. ( the fuel pump cradle).
If it is, what governs the pressure?
Many thanks.

[bikerboywill]

When you say leaking what do you mean? Just a light misting around the cradle? If so it’s probably the rubber o ring has perished like they all do. Just order another one from Nissan and it should be all good.

Also I don’t think they’re pressurised. They must have a breather somewhere which could be blocked I guess but it would make filling up the tank pretty hard

[raddy.]

Fuel tank is keeped under pressure by vent checkvalve and fuel cap vent valve, you can hear evaporated fuel hissing out when opened fuel cap sometimes. Reason is to decrease gasoline vaporisation.