Question Air brakes use ____ to function. Answers Compressed air Liquid nitrogen Carbon dioxide Explanation The brakes in an air brake system use compressed air to function properly. This questions appears in the following tests: Alaska Double Alaska Air Brakes Connecticut Double Idaho Class B Knowledge Test Idaho Air Brakes Iowa Class A Knowledge Test Maryland Air Brakes Minnesota Class B Knowledge Test Minnesota Air Brakes Nebraska Air Brakes New Mexico Class B Knowledge Test New Mexico Double New Mexico Air Brakes Vermont Air Brakes Virginia Air Brakes