Question Some air brake systems introduce alcohol into the system to: Answers Make the brakes work without squeaking. Prevent ice from forming in the brake system. Prevent people from breathing the air from the system. Explanation Some air brake systems contain an alcohol evaporator. An evaporator introduces alcohol into the system to help inhibit the formation of ice in cold weather. Take a FREE Practice Test Now This questions appears in the following tests: New Mexico Knowledge Test Class B , Hawaii Air Brakes ,