TPMS Question

We have been running a Pressure Pro on the rear of our diesel pusher Phaeton for over 8 year using the same set of SS valve stem extensions without any problem. I have never seen any water intrusion as they have "O" ring seals to keep air in and water out of the electronic sensor system.

I just installed a TST system. Love the guys at TST by the way. I called them before ordering and they patiently answered all my questions (many the same as yours) with enthusiasm. I got the 507 system with replaceable batteries. The TST albeit a bit cumbersome to set up, worked flawlessly on our recent 2000 mi trip. As far as extenders- yes they work with extenders. I did have a clearance issue on my F53 front wheel simulators. The simlator (glorified hub cap) did not have enough clearance for the additional room required for the sensor. I used metal snips and trimmed it back (took my time and it looks factory - if you could tell at all). I doubt this is specific to the TST as every system will need additional clearance. I have never heard anyone having to do this so either it's so normal that no one mentions or I have something unique. Hard to believe on the latter. As for immersing them, I can't say. THey work well in rain, but fully submerging them I am not sure. You may want to call the brand you are thinking of. After having a TPMS and allowing me to set my PSI correctly (for a better ride) I would never be without one.

Normally RVers wait until they have a flat tire before investing in a TPMS. You are ahead of the game.
You could also have searched this Forum for `TPMS' then searched the results for `extenders'.

I have TSST system and I am very happy with them, Works great. I have tone one that has owner replaceable battery. The unit has O-ring seal on the sensor housing, Far as putting the sensor underwater, I would call TST and ask them, they are great people to get information from. Let them know you plans and see what they say about it.