What does a governor do in an air brake system?

Answer: B — It regulates air pressure

The role of a governor in an air brake system is to regulate air pressure. It is a crucial component that ensures the air pressure remains within the operational range required for effective braking. The governor monitors the air pressure in the brake system and controls the compressor's operation, allowing it to release or build up pressure as needed. When the pressure drops below a specific level, the governor activates the compressor, causing it to increase the pressure back to the set threshold. Conversely, when the pressure exceeds a certain limit, it prevents the compressor from adding more air. This regulation helps maintain proper function and efficiency of the air braking system, ensuring that the brakes can engage and disengage effectively without experiencing pressure-related failures.