CDL AIR BRAKES ENDORSEMENT
PROFESSIONAL REVIEW HANDBOOK 2026
ACCURATE QUESTIONS ANSWERS
● When should you drain the air tanks?. Answer: After every working
day.
● Why drain water from the compressed air tanks?. Answer: Water can
freeze in cold weather and cause brake failure.
● Air brake equipped vehicles must have:. Answer: A supply pressure
gauge and warning signal when psi drops below 60.
● What can legally hold a parking or emergency brake in position for a
truck, truck tractor or bus?. Answer: Spring pressure.
● What makes the total stopping distance for air brakes longer than that
for hydraulic brakes?. Answer: Brake lag distance.
● The first thing you should do when the low air pressure warning
comes on?. Answer: Stop and safely park ASAP.
, ● The braking power of the spring brakes:. Answer: Depends on the
adjustment of the service brakes.
● The air compressor governor controls what?. Answer: When air is
pumped into the air tanks.
● The application pressure gauge shows the driver how much pressure:.
Answer: Is being applied to the brakes.
● When you apply pressure to the brake pedal, you are.... Answer:
Pushing against a spring and against air pressure to the brakes.
● The air compressor is connected to the engine through.... Answer:
Gears or a V-belt
● Which type of brake is the most common in commercial vehicles?.
Answer: S-cam brake
● An application pressure gauge.... Answer: Shows how much air
pressure you are applying to the brakes.
● All vehicles with air brakes are required to have a low pressure
warning signal. This could be.... Answer: A red light, wig wag
mechanical arm or a buzzer.
PROFESSIONAL REVIEW HANDBOOK 2026
ACCURATE QUESTIONS ANSWERS
● When should you drain the air tanks?. Answer: After every working
day.
● Why drain water from the compressed air tanks?. Answer: Water can
freeze in cold weather and cause brake failure.
● Air brake equipped vehicles must have:. Answer: A supply pressure
gauge and warning signal when psi drops below 60.
● What can legally hold a parking or emergency brake in position for a
truck, truck tractor or bus?. Answer: Spring pressure.
● What makes the total stopping distance for air brakes longer than that
for hydraulic brakes?. Answer: Brake lag distance.
● The first thing you should do when the low air pressure warning
comes on?. Answer: Stop and safely park ASAP.
, ● The braking power of the spring brakes:. Answer: Depends on the
adjustment of the service brakes.
● The air compressor governor controls what?. Answer: When air is
pumped into the air tanks.
● The application pressure gauge shows the driver how much pressure:.
Answer: Is being applied to the brakes.
● When you apply pressure to the brake pedal, you are.... Answer:
Pushing against a spring and against air pressure to the brakes.
● The air compressor is connected to the engine through.... Answer:
Gears or a V-belt
● Which type of brake is the most common in commercial vehicles?.
Answer: S-cam brake
● An application pressure gauge.... Answer: Shows how much air
pressure you are applying to the brakes.
● All vehicles with air brakes are required to have a low pressure
warning signal. This could be.... Answer: A red light, wig wag
mechanical arm or a buzzer.
