By Roger Marble
I recently got this question from a reader:
“I just replaced 6 235/80R 22.5 XRV Michelin tires on my 2013 Monaco Monarch Class A Motorhome. The dealer installed balancing bead bags and new valve stems. I have good access to all valve stems now and have an aftermarket TPMS [tire pressure monitoring system]. A couple of the rears were below the 95-pound alarm point when cold and I decided to add air.
“When I removed the TPMS sensors, the valve stem seats leaked on three of six tires. I replaced the faulty valve stem inserts, completed pressure checks and all is well. I heard from one of my friends that the bead bags are causing the valve stem seat to fail and I understand there are redesigned valve stem seats that solve this issue. Can you comment?”
The dealer that installed the “balance” stuff should have also installed the special valve stem/core air filters. Powder from beads can get into both the core and the TPMS sensor and make them malfunction.
Bolt-in valve stems have a rubber insert on the air chamber side and a large metal washer on the outside. There is a torque spec on the bolt-in valves. This blog post covers valve stems of different types and has the torque spec for the bolt-in nuts.
By “stem inserts” do you mean the valve core? Every valve stem I have ever seen comes with a new core. The only reason for them to leak is some “stuff” got into the new core and most likely was from the balance stuff.
This makes me wonder if the dealer was just interested in selling you the balance beads but didn’t want to kill the sale with an increased cost for the valve air filters; OR he didn’t know that filters were needed when you put “stuff” inside a tire.
Also, did the dealer give you a written tire warranty that covered the use of the balance stuff?