Practice question

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

  1. To control the air pressure levels within the system
  2. To regulate the speed of the vehicle
  3. To activate the brake lights
  4. To maintain tire pressure

Answer: A — To control the air pressure levels within the system

The role of the governor in an air brake system is to control the air pressure levels within the system. It is a critical component that manages the pressure of the compressed air used for braking. When the air pressure in the storage tanks exceeds a specified limit, the governor will activate a signal to stop the air compressor from delivering more air, which helps prevent over-pressurization. Conversely, when the air pressure drops below a certain level, the governor will signal the compressor to start supplying air again, ensuring that the braking system has the necessary pressure to operate effectively. This periodic cycling of pressure helps maintain optimum braking performance and ensures safety while driving. Understanding the function of the governor is essential for properly assessing the overall functionality of the air brake system during a pre-trip inspection.

Practice more: CDL Class B Pre Trip Inspection Practice Exam →