CDL Air Brakes TestDual Air Brake SystemsEasy
The low air pressure warning for a dual air brake system must activate at what minimum pressure level?
- A50 psi
- B80 psi
- C60 psi
- D70 psi
Show answer & explanationAnswer & explanation
Correct answer: C. 60 psi
Federal regulations require the low air pressure warning device (light and buzzer) to activate when the air pressure in either the primary or secondary system drops to 60 psi or below.
Why the other options are wrong
- A. 50 psi is below the warning threshold, meaning the warning should have already been active for some time.
- B. 80 psi is a normal operating pressure, well above the warning threshold.
- D. 70 psi is above the minimum warning threshold.
Low Air Warning Activation Point
The low air pressure warning system is designed to alert the driver when the air pressure in either service brake system drops to a critical minimum level.
- Warning activates at 60 psi or lower.
- Applies to both primary and secondary systems.
- Indicates a need to stop and address the issue.
Memory trick: Sixty is the limit, don't ignore it.