5 replies to this topic

[sparkymae]

This might not be anything but i thought i would check with you guys to be sure. My Mini is a 1990 998cc HS4 carb. Filled it up the other day with fuel, went home, jacked up the right front wheel because i thought i heard a slight noise, just checking. Smelled fuel. Gas was dribbling out of the gas cap. It's a vented locking one. Tank to full? Or not sealing right. Normal?

[cal844]

That's normal as the sealing ring is never perfect.

It is very annoying as you'll be dumping money on the floor

[sledgehammer]

clean the petrol off - as it can damage the original paint
 

it can soften cellulose esp  new paint

[cal844]

clean the petrol off - as it can damage the original paint

it can soften cellulose esp new paint

Yup, I agree give it a gentle wash with car soap and water

[sparkymae]

Thanks for your reply

[Tornado99]

We had similar seal leaks on Ceandess type petrol caps commonly found on Lotus, Triumph cars and norton motorcycles. These are very much like the flip open Monza style found on some minis. To fix the problem on my Norton motorcycle, it needed more than just a fresh sealing rubber ring. It needed more force on the sealing surface. On the bike cap, there is a 1/2" bit of rubber hose sitting on top of the sealing plate, in addition to the actual spring. Renewing that old brittle rubber with new fuel proof hose made a huge improvement. No more full tank leaks.
Ive looked at my mini's flip cap and it doesn't have the rubber hose, just a rather weak spring to put pressure on the seal. I tried stretching the spring out a little to give bit more force. Didnt work. Might try a more robust spring one day.