Question What does an air compressor do in an air brake system? Answers It pumps air into the air storage tanks. It fills the tires. It moves air to the back of the truck. Explanation In an air brake system, the air compressor pumps air into the air storage tanks. The air compressor is controlled by the air compressor governor. Take a FREE Practice Test Now This questions appears in the following tests: Arizona Knowledge Test Class B , California Knowledge Test Class B , Vermont Knowledge Test Class B , Idaho Bus , Michigan Air Brakes , Missouri Air Brakes , Montana Air Brakes , New Mexico Air Brakes , Ohio Air Brakes , Rhode Island Air Brakes ,