Story on a Sprinter RV forum.
Reply to posts on TPMS
"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 , as
suggested, for the front and my local repair shop installed them. I
could not see into the rear dual's 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 did offer a comment that you need the TPMS on for it to provide a warning and I was a bit concerned about the comment on "turning on the TPMS" to check tire pressure.
I am posting this comment to point out what can happen when you use rubber valve stems and an external TPM sensor.