CDL Air Brakes Endorsement Exam
2025 Questions and Answers
A dual air brake system: - --CORRECT ANSWER--Has two separate air brake
systems which use a single set of controls
What part of the truck is the air compressor connected to? - --CORRECT
ANSWER--Engine
Having ABS on only one axle: - --CORRECT ANSWER--Should still give you
more control
When going down a steep downgrade, - --CORRECT ANSWER--The vehicle
should be placed in a lower gear and brakes used to supplement braking
If the vehicle has air brakes, the air compressor drive belt should be checked
before each drive. In what condition should the belt be in? - --CORRECT
ANSWER--Tight
What kind of force must emergency brakes use? - --CORRECT ANSWER--
Mechanical
At what psi is the safety valve set to open? - --CORRECT ANSWER--150
....COPYRIGHT ©️ 2025 ALL RIGHTS RESERVED...TRUSTED & VERIFIED 1
, Using the brakes creates heat. What happens if there is too much heat produced? -
--CORRECT ANSWER--The brakes may not work
What does an application pressure gauge do? - --CORRECT ANSWER--Shows
how much air pressure you are applying to the brakes
Before driving a vehicle with a dual brake system, the driver should: - --CORRECT
ANSWER--Let the air compressor build up a minimum of 100 psi pressure in the
primary and secondary systems
If using the spring brakes when hauling a heavy load, a complete stop will: - --
CORRECT ANSWER--Take a long time
What should happen if the air pressure in the air brake system tanks falls below 55
psi? - --CORRECT ANSWER--The warning light will come on
Why do you need to drain the air tank regularly? - --CORRECT ANSWER--
Because compressed air contains some water and the eater collects in the tanks
When the spring brakes are on, you should never: - --CORRECT ANSWER--Push
the brake pedal down
What do ABS brakes do? - --CORRECT ANSWER--Help you avoid wheel lock
up
In a dual brake system, if one air system is very low on pressure: - --CORRECT
ANSWER--Either the front or rear brakes will not be operating fully
....COPYRIGHT ©️ 2025 ALL RIGHTS RESERVED...TRUSTED & VERIFIED 2
2025 Questions and Answers
A dual air brake system: - --CORRECT ANSWER--Has two separate air brake
systems which use a single set of controls
What part of the truck is the air compressor connected to? - --CORRECT
ANSWER--Engine
Having ABS on only one axle: - --CORRECT ANSWER--Should still give you
more control
When going down a steep downgrade, - --CORRECT ANSWER--The vehicle
should be placed in a lower gear and brakes used to supplement braking
If the vehicle has air brakes, the air compressor drive belt should be checked
before each drive. In what condition should the belt be in? - --CORRECT
ANSWER--Tight
What kind of force must emergency brakes use? - --CORRECT ANSWER--
Mechanical
At what psi is the safety valve set to open? - --CORRECT ANSWER--150
....COPYRIGHT ©️ 2025 ALL RIGHTS RESERVED...TRUSTED & VERIFIED 1
, Using the brakes creates heat. What happens if there is too much heat produced? -
--CORRECT ANSWER--The brakes may not work
What does an application pressure gauge do? - --CORRECT ANSWER--Shows
how much air pressure you are applying to the brakes
Before driving a vehicle with a dual brake system, the driver should: - --CORRECT
ANSWER--Let the air compressor build up a minimum of 100 psi pressure in the
primary and secondary systems
If using the spring brakes when hauling a heavy load, a complete stop will: - --
CORRECT ANSWER--Take a long time
What should happen if the air pressure in the air brake system tanks falls below 55
psi? - --CORRECT ANSWER--The warning light will come on
Why do you need to drain the air tank regularly? - --CORRECT ANSWER--
Because compressed air contains some water and the eater collects in the tanks
When the spring brakes are on, you should never: - --CORRECT ANSWER--Push
the brake pedal down
What do ABS brakes do? - --CORRECT ANSWER--Help you avoid wheel lock
up
In a dual brake system, if one air system is very low on pressure: - --CORRECT
ANSWER--Either the front or rear brakes will not be operating fully
....COPYRIGHT ©️ 2025 ALL RIGHTS RESERVED...TRUSTED & VERIFIED 2
