Home › CDL Practice Tests › Air Brakes Questions › Question 106
Why should spring brakes never be mechanically caged or backed off and left that way for normal driving?
- A.Caging makes the brake apply too strongly
- B.Caging raises the governor cut-out pressure
- C.A caged spring brake cannot apply for parking or in an emergency, removing the fail-safe at that wheel
- D.Caging is only a paperwork concern
Correct answer
C. A caged spring brake cannot apply for parking or in an emergency, removing the fail-safe at that wheel
Why
Caging is a recovery tool for moving a disabled vehicle, not a repair. A truck returned to service with a spring still caged has silently lost its emergency and parking braking at that position.
Manual topic: Air Brakes - Spring Brakes and Parking Brakes · From the Air Brakes practice bank (AB-106).