Home › CDL Practice Tests › Air Brakes Questions › Question 146
When inspecting S-cam brakes, what should you confirm about the camshaft, rollers, and return springs where they are visible?
- A.Return springs are optional if air pressure is high
- B.A binding cam is acceptable on a rear axle
- C.Missing rollers only affect the parking brake
- D.Parts should not be missing, badly worn, broken, or binding, and the brake should apply and release cleanly
Correct answer
D. Parts should not be missing, badly worn, broken, or binding, and the brake should apply and release cleanly
Why
The cam and rollers turn pushrod motion into even lining contact, and the springs pull the shoes back when you release the pedal. Worn or broken hardware causes uneven application, dragging, or a brake that does not fully release.
Manual topic: Air Brakes - Brake Inspection · From the Air Brakes practice bank (AB-146).