absoluTT A3

So I went to check my tire pressure and the metal valve stem caps I installed wouldn't come off. All four of them locked on solid. At first I thought I had been vandalized, that some random delinquent came by and used some metal pipe sealant of some kind. But there was no trace of any kind of residue on stems or caps.

I searched on the Internet and sure enough, it turns out a lot of people from northern climates have run into this problem. Apparently the high salt content in the water from the road activates a bonding between the valve stem and the cap. Supposedly if the stem and caps are of different metals, it accelerates bonding between them . You either have to get valve stem caps with plastic threaded sleeves or periodically apply a generous amount of grease to the valve stems and NEVER tighten the caps on all the way.

Has anyone else here faced this problem? How did you get your metal caps off?

NvrFollo

How 'bout a little anti-seize like u use on spark plugs ?

Reggie

I was thinking that too. Clearly it is due to mismatched metals and the salt

Matt_DTC...noTT

be prepared to buy new stems or tpms sensors. Sometimes we can get them off without having to replace. Car salesman need to educate the consumer about TPMS do's and don'ts, they can be a nightmare if not taken care of.

absoluTT A3

Those caps were on way too tight and there just wasn't enough clearance to get a good grip. Even with tube clamps, there was just no loosening them. Fortunately I found a place that did all 4 wheels for just $42 (including tax). The downside--younger mechanics who managed to nick the rims a little. Oh well. These rims seem particularly prone to nicks anyway--small clearance for the lugs.

I remember checking out the metal ones provided by Audi, and they are metal threaded--no plastic liner. I wonder if they'd suffer the same problem. ANY of these metal cap manufacturers should state a warning about lubrication. This is just plain ridiculous. If you've got a flat in a remote place, you're really screwed.

So yeah, chalk it up to experience. I may go for metal ones again in the future, but not without lubricating them periodically AND replacing them with plastic ones during the winter.