Home › CDL Practice Tests › Air Brakes Questions › Question 46
When checking air build-up at start-up, the pressure rises very slowly and never reaches cut-out. What should the driver do?
- A.Do not drive until the cause is found and repaired; the system cannot be trusted to maintain braking air
- B.Drive slowly and let road speed build the pressure
- C.Keep revving the engine for the whole trip
- D.Block the safety valve so pressure can climb
Correct answer
A. Do not drive until the cause is found and repaired; the system cannot be trusted to maintain braking air
Why
A system that cannot reach cut-out cannot guarantee air for repeated stops. Blocking a safety device to force pressure up is dangerous and never an acceptable workaround.
Manual topic: Air Brakes - Air Compressor and Governor · From the Air Brakes practice bank (AB-046).