Tyre valve

[vectron]

Hi folks, 

one of the tyres on my is 250c is losing air, checking it I need a new valve anyone know which one I need? My car is a 2009 model. 

 

many thanks.

G.

 

[Britprius]

You say the valve is leaking, but can you be more specific as to where? If it is coming from under the screw on valve cap the core of the valve may be loose, and just need tightening. If it has failed the core can be unscrewed and replaced without removing the wheel or tyre.
If the leak is from between the outer part of the valve, and wheel rim try spraying on some WD40 then slacken off the nut part a little, and then re tighten gently. This may cure the leak. If not the valve will need to be removed, and new valve to rim seals fitted.

John.

[vectron]

Thank you John, it’s sending a message to the dash informing me of a low of pressure, I just want to know what valve I need to continue the monitoring system.

[Vintagesixtysix]

Hi Gary does this help...

John has explained fault finding for your individual valves per tyre.

The valve is a schrader type which is universal in modern car tyres......there are different stem types.

The TPMS system is not measuring the pressure of your tyres at the valve ( so not a special valve type) it’s measuring the speed at which each wheel revolves and the onboard computer system then flags the difference up as deflation.

hope helps

phil

[Beamish]

 

Hi Gary,

You can get TPMS "service kits" from either Lexus or E-bay. These contain a new valve core, stem nut and fitting seal. I have just replaced mine as I had the TPMS sensors out to renew the batteries but the original valves and seals were still perfectly OK. Be aware that the valve stem nuts must only be tightened to 4Nm. so be carefull not to overtighten. I got my service kits from Rockauto for under £1 each set where Lexus are five or six times more expensive.

I have to take issue with Phil's comment above that the TPMS system does not measure the air pressure in each individual wheel but rather the change in wheel speed caused by tyre deflation as measured by the ABS/wheel speed sensors. The system in the 2009 IS250C (the IS250 does not have this feature) measures the pressure individually at each TPMS sensor and transmits this info to the ECU. Unfortunately the system only tells the driver that one of the wheels has a loss of pressure but does not identify which wheel. All wheels need to be checked for correct pressure to find the culprit.

Dec.

[Vintagesixtysix]

I am corrected 

Thank you for clarifying Dec.

[vectron]

Thank you Dec.

 

[Britprius]

3 hours ago, vectron said:

Thank you Dec.

 

If you check your tyre pressures you will find which tyre is low. Reinflating the tyre will cure the warning after a short drive. There should be no reason to do anything with the tyre valve unless it is leaking, and is the reason for the low pressure. It could be you have a slow puncture or that the tyre has lost pressure over a long period if you do not check the pressures as you should ar leased every time you fill with fuel.

John.

[OldTrout]

Gary,

Also, the inside of the rim where tyre sits on it may have some corrosion which is causing leaky seal. Removing tyre, cleaning rim and replacing will cure that.

John

[vectron]

Thank you John, 

Lexus Maidstone found the faulty valve and it just needed a new washer!!!! The leak has stopped now to be fair they where excellent, they offered me a 2 service contract for £580 including full parts and Labour and including 2 MOTs my car next year will need a 60 k service.