There are two situations in which valve replacement is necessary.
1 - When changing a tyre
The valve replacement operation is always carried out when you fit a new tyre.
- If it is a rubber valve, it is cut off and replaced with a new one.
- If it is an electronic TPMS (Tyre Pressure Monitoring System) valve, i.e. with a pressure sensor, the entire valve is not replaced, but only the seal inside to maintain the air tightness.
2 - When the tyre valve is porous
In the case of slow pressure loss, there may be porosity in the valve itself, or in the core inside the valve. This is not common, but it can happen.
This porosity compromises the seal, causes abnormal air loss and therefore requires the valve to be replaced, even if the tyre is still in good condition.
Why does this happen?
Part of the valve is made of rubber. As it ages, this material loses its sealing properties. This is why it is recommended that the valve is always changed when the tyre is replaced.
But it may become necessary to replace the valve before the tyre reaches the end of its life. For example, if you only make short trips in the city, the tyre wears little over the years, but the ageing of the valve rubber can make it porous over the years. In this case, the valve should be replaced before changing tyres to avoid pressure loss.
How do you know if the tyre valve is porous?
In any case, it is essential to check the pressure of your tyres regularly.
- If you do not notice any abnormal pressure loss, the valve is still good.
- If, on the other hand, there is an abnormal loss of pressure, the tightness of the valve may be questionable (there may also be other reasons, such as a puncture).
In this second case, have your tyre checked by a professional. If he finds that the valve is porous while the tyre is still in good condition, he will only replace the valve.