Home › CDL Practice Tests › Air Brakes Questions › Question 69
Why do inspectors check the low-pressure warning on every pre-trip rather than trusting it from the last trip?
- A.The warning changes its setting daily
- B.Inspectors check it only for paperwork
- C.Warning switches and buzzers can fail silently at any time, and the driver may get no other notice of a later air loss
- D.The test uses up old air that must be replaced
Correct answer
C. Warning switches and buzzers can fail silently at any time, and the driver may get no other notice of a later air loss
Why
A failed warning is invisible until the moment it is needed, which is why the fanning test is built into the inspection routine. Thirty seconds of testing buys certainty for the whole trip.
Manual topic: Air Brakes - Safety Valve and Low Pressure Warning · From the Air Brakes practice bank (AB-069).