CDL Air Brakes Endorsement Exam
2025 Questions and Answers
To check the slack adjusters on S cam brakes, you should: - --CORRECT
ANSWER--Wear gloves and pull hard on each slack adjuster.
To test the low pressure warning signal, you should (3): - --CORRECT 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: - --CORRECT ANSWER--
From 85 to 100 psi in 45 seconds.
With single air systems, the air pressure should build: - --CORRECT ANSWER--
From 50 to 90 psi in 3 minutes.
To test air leakage rate you should: - --CORRECT ANSWER--Turn off the engine
and release the service brake.
To check the air compressor governor "cut in" and "cut out" pressures (3): - --
CORRECT ANSWER--* Run the engine at a fast idle
....COPYRIGHT ©️ 2025 ALL RIGHTS RESERVED...TRUSTED & VERIFIED 1
, * 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: - --CORRECT ANSWER--100 psi
The governor stops pumping air when it reaches the "cut out" level, or around: - --
CORRECT ANSWER--125 psi
You should use the parking brake: - --CORRECT ANSWER--Any time you park.
To test your service brakes you should: - --CORRECT 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: - --
CORRECT ANSWER--3 psi per minute
The safety valve in the air compressor tank is set to open at: - --CORRECT
ANSWER--150 psi
When the safety valve releases air it means that (3): - --CORRECT 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: - --CORRECT
ANSWER--Bring the vehicle to a safe stop while you still have braking control.
....COPYRIGHT ©️ 2025 ALL RIGHTS RESERVED...TRUSTED & VERIFIED 2
2025 Questions and Answers
To check the slack adjusters on S cam brakes, you should: - --CORRECT
ANSWER--Wear gloves and pull hard on each slack adjuster.
To test the low pressure warning signal, you should (3): - --CORRECT 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: - --CORRECT ANSWER--
From 85 to 100 psi in 45 seconds.
With single air systems, the air pressure should build: - --CORRECT ANSWER--
From 50 to 90 psi in 3 minutes.
To test air leakage rate you should: - --CORRECT ANSWER--Turn off the engine
and release the service brake.
To check the air compressor governor "cut in" and "cut out" pressures (3): - --
CORRECT ANSWER--* Run the engine at a fast idle
....COPYRIGHT ©️ 2025 ALL RIGHTS RESERVED...TRUSTED & VERIFIED 1
, * 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: - --CORRECT ANSWER--100 psi
The governor stops pumping air when it reaches the "cut out" level, or around: - --
CORRECT ANSWER--125 psi
You should use the parking brake: - --CORRECT ANSWER--Any time you park.
To test your service brakes you should: - --CORRECT 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: - --
CORRECT ANSWER--3 psi per minute
The safety valve in the air compressor tank is set to open at: - --CORRECT
ANSWER--150 psi
When the safety valve releases air it means that (3): - --CORRECT 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: - --CORRECT
ANSWER--Bring the vehicle to a safe stop while you still have braking control.
....COPYRIGHT ©️ 2025 ALL RIGHTS RESERVED...TRUSTED & VERIFIED 2
