CDL AIR BRAKES ENDORSEMENT ACTUAL
EXAM SCRIPT 2026 COMPLETE QUESTIONS
ANSWERS GRADED A+
● To test the low pressure warning signal, you should (3): Answer: *
Shut the engine off
* Turn the electrical power on
* Step on and off the brake pedal to reduce air pressure.
● With dual air systems, the air pressure should build: Answer: From 85
to 100 psi in 45 seconds.
● With single air systems, the air pressure should build: Answer: From
50 to 90 psi in 3 minutes.
● To test air leakage rate you should: Answer: Turn off the engine and
release the service brake.
● To check the air compressor governor "cut in" and "cut out" pressures
(3): Answer: * Run the engine at a fast idle
* Pump the brake to reduce tank pressure
* Monitor the air pressure gauge
, ● The governor allows the air to start pumping again when it reaches
the cut in level or around: Answer: 100 psi
● The governor stops pumping air when it reaches the "cut out" level, or
around: Answer: 125 psi
● You should use the parking brake: Answer: Any time you park.
● To test your service brakes you should: Answer: Release the parking
brake, move forward slowly and press the brake pedal.
● A combination vehicle air brake system should not lose air faster than:
Answer: 3 psi per minute
● The safety valve in the air compressor tank is set to open at: Answer:
150 psi
● When the safety valve releases air it means that (3): Answer: * The
pressure has exceeded 150 psi
* Too much air is in the air compressor
* Something is wrong and you should have it checked by a mechanic
● When the low pressure warning is activated, you should: Answer:
Bring the vehicle to a safe stop while you still have braking control.
EXAM SCRIPT 2026 COMPLETE QUESTIONS
ANSWERS GRADED A+
● To test the low pressure warning signal, you should (3): Answer: *
Shut the engine off
* Turn the electrical power on
* Step on and off the brake pedal to reduce air pressure.
● With dual air systems, the air pressure should build: Answer: From 85
to 100 psi in 45 seconds.
● With single air systems, the air pressure should build: Answer: From
50 to 90 psi in 3 minutes.
● To test air leakage rate you should: Answer: Turn off the engine and
release the service brake.
● To check the air compressor governor "cut in" and "cut out" pressures
(3): Answer: * Run the engine at a fast idle
* Pump the brake to reduce tank pressure
* Monitor the air pressure gauge
, ● The governor allows the air to start pumping again when it reaches
the cut in level or around: Answer: 100 psi
● The governor stops pumping air when it reaches the "cut out" level, or
around: Answer: 125 psi
● You should use the parking brake: Answer: Any time you park.
● To test your service brakes you should: Answer: Release the parking
brake, move forward slowly and press the brake pedal.
● A combination vehicle air brake system should not lose air faster than:
Answer: 3 psi per minute
● The safety valve in the air compressor tank is set to open at: Answer:
150 psi
● When the safety valve releases air it means that (3): Answer: * The
pressure has exceeded 150 psi
* Too much air is in the air compressor
* Something is wrong and you should have it checked by a mechanic
● When the low pressure warning is activated, you should: Answer:
Bring the vehicle to a safe stop while you still have braking control.
