Heading home, saw a 500 pulling a tiny caravan coming towards me. Very late, realised it was
@werdna off for the weekend no doubt.
Neighbour got a flat tyre. I pumped it up, and there was no hissing. Not about to jack it up and turn the wheel, as her drive is quite a slope. Did check the valve, no escape.
She popped it down to the tyre shop at the bottom of the road. They removed the wheel, pumped it up, drowned it in the bath, but no air escaping. Popped the wheel back on, gave it back, no charge.
Later I popped next door to check it again, seemd OK, put the presure gauge on it, pressure good, but as I released it, valve hissed. Got it! Valve core playing up, letting air out, but not when checking it. Popped a new core in and pumped it up again. 2 hours later, all still fine.