Many people take their cars in to a garage suspecting that they have a puncture as the tyre seems to be deflating quite quickly after pumping it up. You may be surprised to find out that often you do not have a slow puncture but the air is actually escaping from the rim of the wheel, basically the wheel is not making an air tight seal around the tyre.
This can be due to tyre beading. The tyres should have beading round them to make a tight seal when fitted to the wheel, sometimes this can get damaged and means the beading does not sit within the grove of the wheel.
The other reason for this is that the rim of the wheel is actually damaged and therefore not sitting flush with the tyre. If this is the case sometimes the wheels can be sanded down to make a smooth edge again otherwise the wheel may need to be replaced if damaged badly.
