Home › CDL Practice Tests › Air Brakes Questions › Question 222
Even with an automatic air dryer or automatic drain valves, why should the driver still check the tanks?
- A.Automatic devices can fail, freeze, or become contaminated, and a manual check confirms water is actually being removed
- B.Automatic systems are illegal without daily full draining by law in every case
- C.Checking is only needed to hear the purge sound
- D.Manual drains should be left open at all times
Correct answer
A. Automatic devices can fail, freeze, or become contaminated, and a manual check confirms water is actually being removed
Why
Automation reduces routine water build-up but does not make the system self-inspecting. Finding liquid still collecting, or a device that never cycles, is how a small dryer or drain fault is caught early.
Manual topic: Air Brakes - Air Tanks and Draining · From the Air Brakes practice bank (AB-222).