[RUNNERBUN]

A couple of years back a friend and I were at a meet and he unfortunately experienced two flat tyres in quick succession which left him without a spare. As the second appeared to be a slow leak we decided to add some air via a 12 volt pump which he was carrying.
While we were inflating the tyre we noticed that the air was leaking from the valve passing between the inner metal part of the valve and the rubber outer layer. As a temporary fix we tied an electrical Zippy cable tie around the base of the valve to slow the leak and to our amazement it not only slowed the leak but stopped it all together. A quick inspection of the other valves on the car showed that all were failing in the same way to some degree. All showing some air pockets rising up from the base of the valve. Cable ties were applied to all valves and a couple of years later the ties were still there with no further leaks. The one tube that had failed initially was replaced.