Difficulty in pulling off gas cap

[Sam SL]

I like to know what might be causing such heavy suction of the gas cap to the point where I can turn it but have to yank really hard to separate it from the filler neck.

 

[r44raven]

As far as I know, E500E fuel tanks should run with small internal pressure, not a vacuum. There must be some problem with the tank venting? You need to get this checked A.S.A.P., otherwise you could find yourself with a collapsed tank.

 

[nocfn]

Also, you may want to treat the mating surface of the rubber gasket with some aerospace 303 or auto glym so it slides easier on the unit. Or if it is an old cap, replace it, the gasket or both.

 

[gsxr]

Ditto what was said above. The tank should have pressure, not vacuum. If vacuum is present, there is risk of the tank partially collapsing inward, resulting in reduced capacity and possibly cracking/leaking.