My bicycle tyre deflates air immediately using petrol station's pump@40psi. Tried 10times. never happened b4.

Question

The tyre was partially full which was why I started to pump up. How do I check if the valve core is spoilt. There is no bicycle shop in my area - I've to drag the bic over a few miles for service. So was hoping to fix it myself. How do I start?

Answer 1

Sounds like your valve core is messed up. You can replace it with a new one or one from a different tube. It just screws out, but you need a special valve core remover, some valve caps have it built right on the top. If it's easier just replace the tube.

40 PSI is pretty low for a bike tire, the pressure most certainly did not damage it. They get damaged from filling - using the valve.

Answer 2

Those air pumps pump air way to fast. You should use a hand pump or an electric pump that plugs into a cigarette lighter. Hand pump is best. Also 40 psi sure sounds like an awful lot of air. A car is at 32 psi. I believe you have a hole in the inner tube or the valve core is damaged from too much pressure. Don't pump up the new one that much or you might have the same problem.