CDL Combination Vehicles TestCombination Vehicle Air BrakesEasy
What is the primary purpose of the 'spring brakes' in a combination vehicle's air brake system?
- ATo act as an emergency and parking brake system.
- BTo assist in maintaining constant air pressure in the system.
- CTo prevent wheel lock-up during hard braking maneuvers.
- DTo provide additional braking power during normal stops.
Show answer & explanationAnswer & explanation
Correct answer: A. To act as an emergency and parking brake system.
Spring brakes are designed to engage automatically when air pressure drops to a dangerous level or when activated by the driver, serving as both an emergency and parking brake.
Why the other options are wrong
- B. The air compressor and governor maintain air pressure, not spring brakes.
- C. Anti-lock braking systems (ABS) prevent wheel lock-up, not spring brakes.
- D. Service brakes, not spring brakes, provide primary braking power during normal stops.
Spring Brake Function
Spring brakes utilize powerful springs to apply the brakes when air pressure is lost or when manually activated, acting as both an emergency and parking brake.
- Engage automatically upon air pressure loss.
- Used for parking the vehicle.
- Are held off by air pressure during normal operation.
Memory trick: Springs are for Parking and Emergency stopping.