Why is alcohol added to the air in some air brake systems?
a. Alcohol keeps the system lubricated. b. Alcohol helps prevent the system from freezing in cold weather. c. Alcohol keeps the seals and gaskets from leaking. d. You should never add alcohol to an air brake system. 8. After selecting the proper gear for a steep downgrade, you should: a. Apply the brakes just hard enough to feel a definite slowdown. b. When you are 5 mph below your “safe speed”, release the brakes. c. When you reach your “safe speed” again, re-apply the brakes. d. All the above. 9. Emergency and parking brakes must be held on by mechanical force because: a. They won’t freeze. b. Mechanical force does not require an evaporator. c. Air pressure can eventually leak away. d. All of the above. 10. What does the automatic front wheel limiting valve do? a. Limits the amount of air required to operate the front brakes. b. Limits the pedal pressure required to operate the front brakes. c. Limits the travel of the brake shoes on the front brakes. d. Reduces the air to the front
