Home › CDL Practice Tests › Air Brakes Questions › Question 149
What should you do if one brake on an axle is clearly doing much less work than the other, shown by a much cooler drum after a stop?
- A.Assume the cooler brake is more efficient and keep driving
- B.Add more air pressure by blocking the governor
- C.Report it for diagnosis, because unequal braking can pull the vehicle and overload the working brake
- D.Use the trailer hand valve to balance it at speed
Correct answer
C. Report it for diagnosis, because unequal braking can pull the vehicle and overload the working brake
Why
Balanced braking keeps the vehicle straight and shares heat and wear between wheels. A brake that stays cool while its mate works hard is likely not applying properly, and the working side can overheat and fade.
Manual topic: Air Brakes - Brake Inspection · From the Air Brakes practice bank (AB-149).