At the heart of a commercial vehicle’s air brake system is its air compressor, which pressurizes air in the primary and secondary tanks to provide power for the air brakes and other pneumatic systems.

The compressor is the heart of any air conditioning or refrigeration system, so when it starts showing signs of not working correctly, technicians must act quickly in order to find out what is wrong.

The hottest temperature point in a refrigeration or air conditioning system is on the back of the compressor’s discharge valve, as shown in Figure 1. However, since this point cannot be measured by a ...