My 2019 Fleetwood Discovery got a flat tire after a valve stem failure. The rear inside tire valve stem has an extender that protrudes beyond the outer rim, supported by a rubber spacer. I found the spacer on both rear tires had come loose and slid inward of the outer rim. As I have had the motorhome only 7 months, I cannot recall seeing the spacers, but I never looked specifically for them. The loose spacers allowed the inner valve stem to rub against the outside rim wearing the metal away causing a leak. Both sides of my motorhome are affected one worse causing the flat tire. I had one valve stem replaced to fix the leak . I put a slightly larger rubber spacer to better hold in place. On the valve stem lightly damaged, I pulled forward the existing spacer and used a little silicon glue to more securely attach to rim. Worth a quick look on all motorhomes.
