Home › CDL Practice Tests › Air Brakes Questions › Question 212
On a vehicle without ABS, what is the purpose of releasing the brakes when the wheels lock during an emergency stop?
- A.Releasing pumps more air into the tanks
- B.Releasing lets the wheels start rolling again so grip and steering return, after which the brakes can be reapplied
- C.Locked wheels must be released to prevent the engine stalling
- D.Release is only needed to save lining wear
Correct answer
B. Releasing lets the wheels start rolling again so grip and steering return, after which the brakes can be reapplied
Why
A locked wheel has less grip and no steering response, so briefly getting it rolling again restores control. That apply-release judgement is exactly the task ABS performs automatically on equipped wheels.
Manual topic: Air Brakes - ABS · From the Air Brakes practice bank (AB-212).