The majority of Class A Motorhomes will have steel or metal valve stems (nickel, brass with chrome plating, or a number of other combinations). When we state "metal valve stems" we are referring to the fact that the valve stem is attached to the wheel/rim with a metal device, such as a nut, and is in fact a metal or a non-aluminum alloy.
There are brass valve stems that fit in the category. However, the majority of brass valve stems are surrounded by rubber and use rubber connections to connect to the wheel/rim, making the connection vulnerable to deterioration. The added weight of the TireMinder Flow-Through Adapter coupled with the TireMinder Transmitter may exacerbate the natural deterioration of the rubber valve stem. This is why we do not recommend using the TireMinder Flow-Through Adapters with rubber valve stems.
In regards to aluminum valve stems, you do not need to worry about having aluminum valve stems on your Motorhome. Aluminum is only going to be found on cars, light trucks and SUVs. The TireMinder Flow-Through adapters are NOT COMPATIBLE with aluminum valve stems as it is a dissimilar metal than the metal used on the Flow-Through Adapters. Over time, dissimilar metals will fuse together and destroy both the aluminum valve stem and the TireMinder Flow Through adapter.