Like any mechanical part a tyre valve stem is susceptible to failure and over a lifetime will develop faults that lead to the valve not functioning as originally designed resulting in a leaking tyre valve.
Common reasons for leaks
- Poorly installed valves can lead to leaks, so ensure that when new tyres are fitted you get the tyre fitter to check all the tyre valve stems for any leaks. It might sound a bit crazy but even professionals make mistakes. I personally had one occasion when valve was installed incorrectly and 10 minutes after leaving the tyre center I had a flat. (Sometimes this can be as a result of overtighteing the stem. If your doing this yourself then ensure you tighten the valve to the correct torque setting.)
- Most valve stems are constructed from a combination of metal and rubber parts. The rubber part over a period of time and exposure to UV rays from sunlight will deteriorate with minor cracks appearing on the surface eventually leading to catastrophic failure and a leak.
- Corrosion between the valve stem and allow can happen very quickly as a result of salt being thrown up during the winter season. I notice lots of these failures after an especially cold winter when more road salt is being spread.
- Manufacturing faults are also possible, check the brand of tyre valves you have used and find out if the manufacturer has issued any recall notices, with the internet this is becoming easier. If this is the case and you don’t want to risk a similar failure then pick a set of valves from a reputable manufacture when you come to replace the tyre valves.
- On very rare occasions you may have someone maliciously messing around with your valve stems, hard to tell but if you notice a regular pattern in valves failing then you could be at the wrong end of such behaviour.
As mentioned above there are numerous reasons a tyre valve begins leaking and it could be a combination of the above causes. Its good practice to change your valve stems whenever you replace your tyres. Always check your tyre valves for leaks when your inflating or defeating your tyres.