Why must air tanks be drained regularly on a system without a working air dryer, especially in cold weather?

• A.Water in the tank makes the air too heavy to use
• B.Collected water can freeze, block the air flow, and leave you without normal braking
• C.Draining keeps the tank paint from fading
• D.Draining is only done to check the tank color

Why

Compressor oil and condensed water collect at the bottom of every tank. In winter that water can freeze in lines and valves, and in any season it takes up space meant for stored air.

Manual topic: Air Brakes - Air Tanks · From the General Knowledge practice bank (GK-127).

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?
• Why does an air dryer matter to the health of an air brake system?
• Some older air systems use an alcohol evaporator. What problem is it meant to prevent?