A basic air brake system capable of stopping a vehicle has five main components:
- A COMPRESSOR, to pump air
- A RESERVOIR OR TANK, to store the compressed air
- A FOOT VALVE, to regulate the flow of compressed air from the reservoir when it is needed for braking
- BRAKE CHAMBERS & SLACK ADJUSTERS, the means of transferring the force exerted by the compressed air to mechanical linkages
- BRAKE LININGS AND DRUMS OR ROTORS, to create the friction required to stop the vehicle
It is necessary to understand how each of these components works before studying their functions in the air brake system.