My Mazdaspeed is equipped with TPMS (Tire Pressure Monitoring System). When the pressure in any wheel differs from specified standard, the indicator light is shown on dashboard. This usually happens when pressure decreases due to a hole in the tire, leaky valve or damaged rim. Good practice is to check pressure in wheels from time to time regardless of TPMS sensors, but when the indicator lights up on dashboard, it should be done as soon as posible, even if you do not see any loss. Unfortunatelly, the presure sensors has defect, that metal parts corrode after few years and can split or broke. That is what happened with my sensor when I drove to check tire pressure on petrol station. When I connect hose nozzle with air, the sensor broke and I was left with valve in my hands and an air stream from my rear wheel. In this kind of situation you could not even use of the special foam, which is now often included in car equipment instead of spare wheel. Fortunatelly my Mazdaspeed is equipped with spare wheel, so I made replacement and went home. Next day I began research for a repair kit for TMPS sensors.
When I called to Mazda dealership, I heard that manufacturer does not provide repair kit for pressure sensor and I need to replace whole sensor, which costs about 500 PLN ($160) plus cost of the service (registering new sensor in vehicle computer). Afterward I found used sensor on auction portal for about half of the price. But why to replace the whole sensor, when the electronic is good, and only mechanical part is damaged? So I've done a further research and I found a replacement kit only for mechanical part for about 65 PLN ($20) plus shipping.
I had to buy a Torx screwdriver set for mobile phones ($3) yet, to unscrew one screw, but the rest has gone smoothly. Rapair kit also includes a new gasket and a nut, so you do not need to worry about old ones during dismounting. Also there is no need to make any changes in vehicle computer, because the sensor is the same.