Leaking fuel cap - defender

[JST]

OK, so plan is two fold.

firstly make sure the exisiting venting system is working and put together right, then check for leaks.

plan two is to extend the breather with a T peice on the exisiting breather, its ID 12mm and i can get 12mm T pieces but where do you get 12mm pipe from? or i may fit a reducer and then smaller pipe to run up the side of the cage.

back to plan one. i have added some inner tube behind the exisitng outer edge seal to ensure the fit is good all round, the exisiting system was indented so you coudl see where the rim of the filler pushed into it but there was a spot with no indentation which could have been the cause.

Also looked inside, it looks like this:

there is a blackl plastic rocker at 8 O'Clock which has a clear plastic ball under one side and a metal ball under the other - what does this do? the plastic ball was stuck in there when i first took it apart, also the rocker has a small ridge on it (underside in this photo) should this be as it is or the other way up? other way up ir eckon to stop the rocker just sticking to the back of the top plate.? any thoughts. there is also another spring loaded metal ball at 2 O'Clock, blowing down the tube, compresses the spring that releases the ball bearing so air flows, is this correct?

with the rocker removed it looks like this:

any ideas on what each ball does or how it should work?

Plus if i wanted to make the system sealed i guess i can jsut block up the 3 holes as illustrated above?

[bishbosh]

I'm just guessing here, but surely the relative densities of the two balls at 8 o'clock is the key?

I would suggest that the metal ball keeps the vent open during normal service and the plastic ball floats in the fuel and closes the vent during off camber moments?

If the plastic ball was stuck maybe that was your problem and the vent wasn't closing?

[JST]

Bish - yep reckon you are right and TC confirmed thats what they did, so stuck plastic ball was/is prob the problem. will be going for Jases suggested and extended breather and sealed cap anyway i reckon.