Home › CDL Practice Tests › Air Brakes Questions › Question 159
What happens when pushrod stroke becomes excessive?
- A.The chamber can run out of useful travel, so braking force falls and stopping ability is reduced
- B.The brake applies harder because the pushrod travels farther
- C.The linings last longer because they touch the drum later
- D.Only the parking brake is weakened
Correct answer
A. The chamber can run out of useful travel, so braking force falls and stopping ability is reduced
Why
Air pressure creates force only while the diaphragm and pushrod can still move and press with effective leverage. Excess travel uses up that range, changes the adjuster angle, and leaves the brake weak even at full system pressure.
Manual topic: Air Brakes - Slack Adjusters · From the Air Brakes practice bank (AB-159).