What is the purpose of the governor in an air brake system?

The governor in an air brake system plays a crucial role in controlling the operation of the air compressor. It regulates the air pressure within the system by starting and stopping the compressor at predetermined pressure levels. When the air pressure in the system drops to a specific level, the governor activates the compressor to build the pressure back up. Once the pressure reaches a set limit, the governor will stop the compressor to prevent over-pressurization. This automatic control helps ensure that the brakes function effectively and that there is always sufficient air pressure available for safe braking performance.

In contrast, regulating air temperature and filtering air contaminants are not functions of the governor in the air brake system. While air temperature can have an impact on performance, it is managed through separate components. Likewise, parking brake engagement is typically controlled through different mechanisms, and does not involve the governor’s function related to the compressor.