Why does an air dryer matter to the health of an air brake system?

• A.It increases tank pressure beyond the governor setting
• B.It dries the tread of the tires in wet weather
• C.It cools the brake drums after long descents
• D.It removes moisture and oil vapor from compressed air before that air reaches the tanks

Why

Water in the tanks can freeze in cold weather, block lines, and corrode valves, while oil vapor damages seals. The dryer strips most of that contamination out and purges it in a short burst of air.

Manual topic: Air Brakes - Air Dryer · From the General Knowledge practice bank (GK-104).

Practice this subject as a full test

More Powertrain & Brake System Basics questions

• What does the air compressor governor do once air tank pressure reaches its cut-out setting, which is typically around 125 psi?
• At about what air pressure does the governor cut the compressor back in so the system can rebuild pressure?
• What is the job of the safety valve fitted to the first air tank reached by the compressor?
• Some older air systems use an alcohol evaporator. What problem is it meant to prevent?
• On a vehicle with a dual air brake system, what does having two separate systems give you?