I continue to see posts from RV owners saying they have "Rubber" valves. This even though most rubber valves are only rated for 65 psi cold. There are some rubber valves rated for 80 and even some rated for 100 psi but these are not interchangeable.
How can you tell if you have the correct rubber valve for your application without dismounting the tires?
A quick examination should give you an idea of what you have.
What to look for
First unscrew the cap. See if the the only metal you see is the threaded part right under the cap. This is just over 3/8" long.
This valve is usually about 1-1/4 long outside the wheel. Is designed for a hole in the wheel of 0.453 and is rated at 65 PSI Max Cold inflation.
If you see metal even with the cap on like this
It is either a 600HP series LIKE THIS which is rated for 80 psi Max Cold inflation or a 801HP series rated for 100psi Maximum Cold inflation.
NOTE these are NOT interchangeable as the 600 is designed for a rim hole of 0.453" while the 801 needs a hole diameter of 0.625".
Now even if your cold tire pressure does not exceed the rated capacity for the valve you have I strongly suggest you consider switching to a bolt in metal valve with the appropriate rim hole size as if you run valve extenders or hoses or external TPMS you are probably applying more side load to the valve that it was initially designed to accept.
Also you should be running metal valve caps not the cheap plastic ones that probably were OE for if the valve core leaks due to a bit of dirt the metal cap can hold much more pressure than the plastic one.
NOTE if still in doubt you should have the valves inspected by a tire dealer. Call and ask if they have a Technician ASE Certified on tire inspection. If not, select another dealer.