THE HUMBLE VALVE CAP is the component most reported missing on any used car. Most people don't give it another thought; even engineers carrying out a pre-purchase inspection for intending new owners might not think to mention it. That could be a mistake.
"Ask yourself why there are valve caps at all," said Ken Mann, business communications advisor, for mytyres.co.uk. "Nobody would suggest that they have the safety status of air bags or seat belts, but they do have a job to do - one that is disproportionate to their size."
Without the cap to act as a shield, dust and other minute debris from the road surface will settle around it. Together with water spray on wet roads, this could cause the valve to become 'sticky' in operation. Next time you re-inflate your tyres to the correct pressure, the valve may not close properly - leaving you with a decidedly flat feeling. Or it may leak air over the course of a journey, allowing the tyre to become soft and increasing heat build-up. If it does, there are consequences for the safe handling of the car, especially during cornering - and the average driver may not be able to discern anything is wrong until it's too late. It's another reason to check your tyres at least once a week - and to ensure valve caps are replaced if they are missing.