An estimated 300 million tire pressure monitoring system (TPMS) sensors are in service right now, and tire dealers who are not servicing TPMS are letting revenue opportunities drive out of their shops, according to an automotive service trainer.
In this Q&A, Billy Johnson, a technical trainer for Tech International, a producer of tire repair and wheel service products, explains the importance of TPMS service and how to address common concerns.
Q: How frequently should TPMS components be serviced?
A: In addition to replacing the TPMS sensors when battery life ends—approximately five to seven years—it is recommended that technicians service the other TPMS components every time a tire is removed from the rim.
This includes replacing all of the components used to connect the TPMS sensor to the rim, often referred to as a service kit. TPMS service kits may include a grommet and seal, hex nut, valve core, valve cap and metal washer depending on the type of vehicle and type of valve.
Q: Why do I need to replace the TPMS service kit so frequently?
A: Our industry should look at the TPMS service kits as “maintenance kits.” By following industry recommendations to replace TPMS components each time a tire is removed from the rim, we can prevent corrosion of the valve core and stem. Valve corrosion not only leads to TPMS failure, but can lead to tire failure due to loss of inflation pressure.
As tire repair experts, it is our responsibility to share the importance of TPMS maintenance with our customers. This helps to build our relationships with customers by addressing an important safety issue—and allows for new sales opportunities.
Q: What do I do if the valve stem is already corroded?
A: Whenever you service TPMS, it is important to “test before you touch” to address any issues, like corrosion, before you begin service. If a TPMS valve stem is corroded, you should communicate that to the customer before servicing the unit. In many cases, this will require that the valve stem and/or sensor be replaced in order to prevent any future air loss in the tire.
There also are special tools available that allow tire technicians to drill out a corroded valve and install a new one, even in some cases where the valve is broken.
Q: Can I prevent valve stem corrosion?
A: In addition to servicing TPMS components regularly, corrosion may be prevented by simply ensuring the valve cap is on. Valve caps can be forgotten easily or left off valve stems for quick pressure readings, but when a valve cap is missing, that exposes the core to the elements, which can lead to corrosion and leaks.
Replacing a metal valve stem with a rubber snap-in equivalent—which will leave virtually no metal exposed to the elements—is another option. This also will eliminate the chance for galvanic corrosion with the valve stem and valve core both being the same type of metal.
It also is important to ensure that you do not over-torque the valve core in a clamp-in valve stem, which can strip the nickel plating off of the valve core. This will expose the brass body of the valve core and lead to galvanic corrosion.
Billy Johnson has been a technical trainer with Tech International, a global supplier of tire repair and wheel service products, for eight years. He holds a bachelor's degree from Slippery Rock University, is a Tire Industry Association-certified Commercial Tire Service Instructor and is an Advanced Automotive Tire Service Instructor. More information from Tech International about tire repair is on its website at www.techtirerepairs.com/training.htm.