Home › CDL Practice Tests › Air Brakes Questions › Question 6
What part applies the service brakes when air pressure is delivered to it at each wheel?
- A.The brake chamber, which pushes the pushrod and slack adjuster
- B.The air dryer cartridge
- C.The governor diaphragm only
- D.The reservoir drain valve
Correct answer
A. The brake chamber, which pushes the pushrod and slack adjuster
Why
Air entering the brake chamber moves a diaphragm and pushrod, which turns the slack adjuster and cam to force the shoes against the drum. Without that chamber action, tank pressure alone cannot create braking at the wheel.
Manual topic: Air Brakes - Air Brake System Components · From the Air Brakes practice bank (AB-006).