Characteristics of dual air brake systems include:
Answer: A
One brake pedal operates two separate air braking systems.
With a dual air brake system, the brake pedal operates two separate air brake systems. The primary air brake system controls the tractor's rear brakes, and the secondary system controls the tractor's front brakes.
All choices
- AOne brake pedal operates two separate air braking systems.
- BThe two systems are split diagonally, each controlling one front brake and the opposite rear brakes on the tractor.
- CThe two systems are split side-to-side with one controlling the left of the tractor and the other controlling the right.
Why the other answers are wrong
B. The two systems are split diagonally, each controlling one front brake and the opposite rear brakes on the tractor.
Choice B is wrong because dual air brake systems are not split diagonally but operate two separate systems controlled by one pedal.
C. The two systems are split side-to-side with one controlling the left of the tractor and the other controlling the right.
Choice C is wrong because the two systems are not split side-to-side but are separate front and rear systems.
CDL Air Brakes Test Info
Questions on Exam
25
Passing Score
80%
Time Limit
Typically 30 minutes; varies by testing location
The Air Brakes test content is federally standardized, so this question applies in every state. Age limits, fees, and testing procedures do vary — check your state's CDL requirements.
Ready to pass your CDL Air Brakes exam?
Get full practice exams, study mode, and simulated tests with detailed explanations.
Risk-free — cancel anytime, no charge until trial ends.
More CDL Air Brakes Practice Questions
- The driver must be able to see a low air pressure warning which comes on before pressure in the service air tanks fall below ____ psi.
- The safety valve is set automatically when pressure is:
- Parking or emergency brakes of trucks and buses can be legally held on by ____ pressure.
- Why drain water from compressed air tanks?
- Repeatedly partially increasing and pressing the brake pedal may result in: