My car went for its service yesterday and they could not get the wheel valve covers off .
When i got the car home i had to cut them off
They are alloy ones and the road salt had corroded them on
SO CHECK YOUR VALVES
Jacko

Common issue and getting worse as more cars have these fitted with pressure monitoring sensors inside the rims.

Peugeot 407's seem particularly bad. We cringe at having to check their pressures as the valve end has been known to simply break off doing it.

What's wrong with old fashioned plastic ones?

quote:

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Originally posted by Slimy38
What's wrong with old fashioned plastic ones?

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Ah, were these ally caps on rubber valve stems? Yes, they can be a pain to remove and you're better off with plastic caps. I was thinking of ally, bolt in, valve stems in my first post.

I remember hearing this happen loads of times years ago, its something to do with a chemical reaction between the alloy valve cap and the steel threaded part of the valve. It mostly seems to happen when cheap anodised valve covers are bought cheap from discount parts stores and given away free on max power type magazines.

There is indeed a chemical reaction between aluminium and steel.
This very reaction is used to weld railway track.

On a much smaller scale aluminium pop rivets react with the steel mandrel pin
which is why their use is banned for repairs in car floors for MOT.

The IVA hasn't cottoned on to this yet.


Paul G

Valve stems are brass, the caps are disimilar metal,the problem is I believe caused by electrolysis? Can be very expensive with TPMS sensors