What do air brakes use to make the brakes work? Do you currently have car insurance? Insurance is mandatory to drive in Ohio Yes I have insurance. But please show me your best quotes. No, please help me find the best insurance. Question What do air brakes use to make the brakes work? Answers Compressed air Outside air Non-compressed air Explanation Many large CMVs are equipped with air brakes. An air braking system uses compressed air to operate. This questions appears in the following tests: Arizona Air Brakes Arkansas Air Brakes California Class A Knowledge Test California Air Brakes Hawaii Class B Knowledge Test Idaho Bus Iowa Air Brakes Kentucky Air Brakes Kentucky Air Brakes Louisiana Bus Louisiana Passenger Louisiana Air Brakes Michigan Air Brakes Minnesota Air Brakes Missouri Double Montana Class B Knowledge Test Montana Air Brakes Nebraska Class B Knowledge Test New Hampshire Air Brakes North Carolina Air Brakes Ohio Air Brakes Oregon Air Brakes South Carolina Air Brakes Washington Class B Knowledge Test Wisconsin Class A Knowledge Test Wyoming Air Brakes