Is this a common problem. Came to inflate a tyre on the van which had developed a flat this week, only to find the valve had perished. Put the spare on & thats the same. I had the tyres fitted to some different wheels 3 years ago & I presume they changed the valves. Maybe not or maybe they used cheapo valves.
I’ve never seen a perished valve as in the rubber bit. Quite possible that they weren’t changed at last tyre swap. It’s common for the metal part to corrode especially if metal dust caps are fitted.
Thats obvious, but it is on the inside of the rim not subject to UV, even if it fails there is no chance of the valve blowing out.
Yes mine have perished in the same place. I am a bit reluctant to fit metal valves. I see a lot on vehicles at work that have TP monitors & the cap threads often corrode. The cap seizes on, have to remove them with mole grips & they often snap off.
Rubber valves have a metal thread as well. Same problem if you have metal caps and don't check your tyre pressures regularly. Nothing to stop you fitting plastic caps.
If you don’t need valves with the TPM’s nickel plated should reduce the corrosion issue. https://www.raceways.co.uk/Nickel_plated_Outer_Mount_tyre_Valve_Stem.htm