The following procedure describes the tools, materials and technique to suspend the TPMS on a 2010 Toyota Corolla race car. You will build a plastic pressure vessel that maintains a uniform air pressure on the sensors. This vessel, constructed of 3” PVC pipe, must be carried in your vehicle in order to transmit the proper signal to the car’s computer.
This modification is strictly intended for use in competition vehicles for use only in sanctioned motor racing activities. TPMS is a valuable safety assist for motorists. Remove the assembly described here along with competition tires before returning the vehicle to public roads.
I am not responsible for any damage or injury to you or your car.
The TPMS sensor described here is “Pacific” brand, model number PA66-GF33. Its dimensions are:
BTW, this sensor weighs 1.3 ounces, so when you replace it with a conventional rubber stem, you must rebalance the tire/wheel assembly.
3” x 4.5” section of Schedule 40 or Schedule 80 PVC pipe
3” PVC cap*
3” female weld/thread coupling
3” threaded plug
PVC cleaner, primer and cement
J B Weld epoxy
Schrader valve, such as McMaster-Carr
part number 8063K31
One 1/8” NPT hex nut and M10 washer.
* fittings must be “thick wall” style, suitable for water supply, not “thin wall” style, used on drain pipe. This photo illustrates the difference. Thick wall is 0.239”, thin is 0.118”.
Seal one end of the pipe with the cap. Caution: PVC pipe is expressly prohibited for use with compressed air. The fact that many home and automotive shops use PVC pipe for this purpose should not lull you into sloppy assembly techniques. All materials must be clean and at room temperature. Use PVC cleaner and primer on both surfaces before cement, per the manufacturer’s instructions.
Attach the coupling to the other end of the pipe. Allow these joints to cure undisturbed for 24 hrs. at room temperature.
Be careful to join and cure the assembly with the coupling “up”, so that the threads are not contaminated with cement.
Drill a 3/8” hole in the center of the pipe plug. Use a drill press to ensure a clean, straight hole.
Mount the Schrader valve in the hole. A little JB Weld on the threads and under the washer won’t hurt. Use a box wrench and socket to apply sufficient torque to the valve (7/16”) and nut (½”). Allow the epoxy to cure for 24 hours at room temperature.
Place the 4 sensors in the container, cushioned with some paper. Bubble wrap or foam will be crushed by the air pressure. Cement the plug, and allow to cure for 24hrs. Pressurize the assembly with a bicycle pump to 30 psi. Submerse the assembly in a bucket of water to check for leaks. Mount the assembly securely to the race car chassis, and include its removal procedure on your post-race checklist. Reset the TPMS system in the car upon arrival and departure from the race track with the procedure described in the Owners Manual.
The threaded plug is used on this assembly because the thick wall of this pipe and connectors prevents a conventional rubber Schrader valve from seating. The threaded valve described here requires two parallel flat surfaces, well-provided by the square hole plug. I originally tried to use pipe dope and/or Teflon tape to seal the plug, but the joint could not withstand 30 psi. The threaded coupling would have made battery replacement easier. You may have better luck with this joint, but the cost of the assembly is so low that total replacement is insignificant.