Home › CDL Practice Tests › Air Brakes Questions › Question 137
During an inspection you hear a steady hiss near a brake valve after the brakes are released. What does that most likely indicate?
- A.Normal operation of the air dryer on every cycle
- B.The brake linings seating against the drum
- C.The governor cutting in at the correct pressure
- D.An air leak that should be located and repaired before driving
Correct answer
D. An air leak that should be located and repaired before driving
Why
Audible leaking air after application or release points to a valve, hose, chamber, or fitting that is not sealing. Small leaks grow under vibration and heat, and a system losing air can fall to warning and spring-brake pressure.
Manual topic: Air Brakes - Brake Inspection · From the Air Brakes practice bank (AB-137).