Some help for a "stupid" guy please.
I replaced the valve caps with aloy ones a time ago. Yesterday I wanted to check on tire-pressure and ... I just could remove one, the others seems to be oxidated and do not come off.

I tried with special oil and by warming up the cap, but no relief.

Has anyone a hint how to get them off, please.

thanks and regards,

Patrick

 

I had the same problem with some caps that had brass inserts. Normally this would be good but the valves on this car don't have brass threads, they're some type of grey metal. I think there was some kind of galvanic reaction with the brass in the caps and even though they were only on a week or so they were very hard to remove. I'd just stick with the plastic caps or caps with plastic threads.

Sorry, don't have any bright ideas about removing other than you might have to take some tools to 'em. I'd be very careful applying any heat -- you don't want to ruin the rim seals or the TPMS sensors.

 

Nubo,

Thanks for your reaction, I feel a bit better knowing that I'm not alone with this problem and that a sort of reaction is the cause.

Anyway, I have an appointment with my tire specialist today, so if I have news on this I will inform you, perhaps warn everyone about this.

Thanks and have a nice day.

Patrick

 

Did you try some penetrating lubricant, like WD-40?

 

Yes, Omicron. But my wheel-specialist is aware of that "corrosion" problem. He will solve it tomorrow and advices me special oil for cuper. I'l give full report tomorrow.

regards and thanks
Patrick

 

I've got the metal rotor-shaped RX-8 valve stem caps from Mazda and they are harder to unscrew than plastic ones, but I can always get them off. I guess the metal on metal is the culprit. Sometimes I have to get rubber gloves so I can get a better grip before I can get them to unscrew.

 

next time you install them, you might try: teflon tape, motor oil, or teflon paste to prevent the corosion. I think the paste wouls work the best.

 

Hi all,

Reparation done : they removed 2 valves (rear) and replaced them. They put on metal valve caps but indeed with some grease in them (that was my fault !).

They checked the alignement and had to make some minor corrections based on the map somewhere in the item Wheels-Tires. Those specs are not the same as those for the '95 RX7 but are close to them. The rear train seems a bit more stable.

I will try it out as tomorrow I drive off for Germany (800 km) to pay a visit to my family there. Early next week I will inform you all of my experience at higher speeds.

regards and do all have a nice long weekend.
Patrick

 

I'd advise against the use of petroleum-based oil or grease on the valve threads. There's a chance a small amount could be introduced into the valve during inflation. Schrader (car tire) valves seal by means of a small bit of rubber in the valve core. Petroleum products tend to ruin certain kinds of rubber. I don't know how likely this is to happen but having air in the tires is pretty important. Teflon (plumber's) tape might be a better choice for this application. If you'd still rather use grease, then use it very sparingly, just enough for a thin film so that excess doesn't get into the valve.

I still think the best solution is caps with non-metallic threads.

 

Hi, Nubo

In the end I agree with you and replaced the metal ones with the original ones (non-metallic).

Thanks to you all for your reactions.

Patrick