What is a tyre valve? When should it be replaced? And how is it replaced? You can find the answer to all these questions in our article.
What is a tyre valve?
A tyre valve is a part of every tyre. It keeps the tyre sealed and prevents air from escaping. It is used to inject air into the tyre so that it is at the correct pressure.
A valve consists of three parts:
- the body made of rubber and grooves for screwing in the cap,
- the cap,
- the core, which looks like a metal rod, and which is in the centre of the body (the red part is the seal)
A valve must always have a cap to prevent air loss. So, if you find that one of your valves no longer has a cap, it is essential to replace it.
When should the tyre valve be replaced?
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.
A little trick to find out if the valve is porous:
Make sure that the cap is screwed on tightly, then wiggle the valve back and forth. If you hear little noises of air escaping, it is porous.
You can also wet the valve with soapy water before wiggling it: if there is an air leak, it will show up as small bubbles.
How is a tyre valve replaced?
The valve replacement procedure requires two things:
- Knowledge of how to do it,
- To be equipped with the accessories and machines used by professionals in order to remove the tyre, replace the valve (or the inner seal if it is an electronic valve), adjust the wheel balance according to the information transmitted by a machine designed for this purpose.
Without this knowledge and equipment, replacing a valve can be risky and then constitute a risk on the road. That's why we recommend that you take your tyre valve replacement to a professional. To find one near you, you can use our tool below: