Our Motorhome came with valve stem extensions, the braided steel ones. The one on the street side worked fine, but the one on the curb side some times would have trouble airing up or checking tire pressure. I adjusted that one and re-installed and it was fine after that.
When we replaced the tires last year, we purchased a set of
Tireman valve stems. These are a one piece valve stem, not extensions. They are pricey, but they are worth the piece of mind and the ease of airing up. Since we had them installed with the new tires, we weren't charged extra for installing them.
-Michael