Home › CDL Practice Tests › Air Brakes Questions › Question 23
In an air disc brake, what creates the clamping force on the rotor instead of an S-cam spreading shoes?
- A.A hand cable pulls the pads together
- B.Centrifugal force throws the pads outward
- C.Vacuum from the intake manifold clamps the pads
- D.Air pressure drives a mechanism that squeezes brake pads against a rotor (disc)
Correct answer
D. Air pressure drives a mechanism that squeezes brake pads against a rotor (disc)
Why
Air disc brakes use chamber pressure to actuate a caliper that clamps pads to both sides of a rotor. They share the same air supply and controls as drum systems even though the foundation brake itself works differently.
Manual topic: Air Brakes - Air Brake System Components · From the Air Brakes practice bank (AB-023).