with RV tire expert Roger Marble
This is a comment I came across on a TPMS story on a Sprinter RV forum:
“My new tire pressure monitoring system just saved our just-completed trip to Florida. Thanks to you all I thought I had, and paid a lot, to Mercedes to replace my rubber valve stems and add metal valve extenders for my sensors. If you remember, I did see the front wheel valves Mercedes did NOT replace with steel. I did get BORG valve stems from ShinyRV.com, as suggested, for the front and my local repair shop installed them. I could not see into the rear duals to check.
“Well, you were right. After about 2000 miles into our trip, I turned on the TMPS to check pressures. The warning came up right away on one of the rear tires, 7 PSI. Sure enough, after five hours just off of interstate 75 in Florida, Mercedes had roadside assistance change to the spare (still have warranty). I added some air to the flat tire and soaped the rubber valve to verify that’s what caused the leak. It didn’t seem like a rub through but I did see cracks (must be from vibration).
“We drove 160 miles to a tire repair shop in Georgia. They put in small rubber valve stems in the spare and all four rear tires because I couldn’t trust the rubber valves. All TPM sensors were removed from the rear wheels. Lesson learned: TIRE PRESSURE MONITORING IS A MUST ALONG WITH STEEL VALVE STEMS. Rubber ones will crack and leak. I will order BORG steel valves for the rear wheels.”
I was a bit concerned about the comment on “turning on the TPMS” to check tire pressure, and I did offer a comment that you need the TPMS turned on for it to provide a warning.
I am posting this comment to point out what can happen when you use rubber valve stems and an external TPM sensor.