TEXAS CDL AIR BRAKES EXAM, PRACTICE EXAM AND
STUDY GUIDE NEWEST 2024 ACTUAL EXAM 250
QUESTIONS AND CORRECT DETAILED ANSWERS WITH
(VERIFIED ANSWERS) |ALREADY GRADED A
Air brake systems combine what three different systems? - ANSWER: Service brakes,
parking brakes and emergency brakes.
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.
To test service brakes you should... - ANSWER: Release the parking brake, move
forward slowly and depress brakes.
Stab braking occurs when you... - ANSWER: 1. Press on a brake pedal as hard as you
can. 2. Release the brakes when the wheels lock up. 3. Apply the brakes when the
wheels start rolling.
Air brakes take longer to stop than hydraulic brakes because... - ANSWER: It takes
longer for the air to flow through the lines.
The proper way to go down long grades is to... - ANSWER: Apply brakes just hard
enough to reduce speed to 5 mph below safe speed then release until back to safe
speed and repeat process.
When should you avoid using the parking brake? - ANSWER: When the brakes are
hot.
If your vehicle has an alcohol evaporator, everyday during cold weather you should: -
ANSWER: Check and fill the alcohol level.
During normal driving, spring brakes are usually he'd back by what? - ANSWER: Air
pressure
In air brake vehicles, the parking brakes should be used when? - ANSWER: Whenever
the vehicle is parked.
The brake pedal in an air brake system does what? - ANSWER: Controls the air
pressure applied to put on the brakes.
If your bus has dual parking control valves it means that you can use pressure from a
separate tank to: - ANSWER: Release the spring brakes to move a short distance.
A straight truck or bus air brake system should not leak at a rate of more than ____
PSI per minute with the engine off and the brakes released. - ANSWER: 2
An alcohol evaporator does what? - ANSWER: Reduces the risk of ice in the air brake
valves in cold weather.
If you must make an emergency stop, you should brake so that you: - ANSWER: Stay
in a straight line and can steer.
STUDY GUIDE NEWEST 2024 ACTUAL EXAM 250
QUESTIONS AND CORRECT DETAILED ANSWERS WITH
(VERIFIED ANSWERS) |ALREADY GRADED A
Air brake systems combine what three different systems? - ANSWER: Service brakes,
parking brakes and emergency brakes.
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.
To test service brakes you should... - ANSWER: Release the parking brake, move
forward slowly and depress brakes.
Stab braking occurs when you... - ANSWER: 1. Press on a brake pedal as hard as you
can. 2. Release the brakes when the wheels lock up. 3. Apply the brakes when the
wheels start rolling.
Air brakes take longer to stop than hydraulic brakes because... - ANSWER: It takes
longer for the air to flow through the lines.
The proper way to go down long grades is to... - ANSWER: Apply brakes just hard
enough to reduce speed to 5 mph below safe speed then release until back to safe
speed and repeat process.
When should you avoid using the parking brake? - ANSWER: When the brakes are
hot.
If your vehicle has an alcohol evaporator, everyday during cold weather you should: -
ANSWER: Check and fill the alcohol level.
During normal driving, spring brakes are usually he'd back by what? - ANSWER: Air
pressure
In air brake vehicles, the parking brakes should be used when? - ANSWER: Whenever
the vehicle is parked.
The brake pedal in an air brake system does what? - ANSWER: Controls the air
pressure applied to put on the brakes.
If your bus has dual parking control valves it means that you can use pressure from a
separate tank to: - ANSWER: Release the spring brakes to move a short distance.
A straight truck or bus air brake system should not leak at a rate of more than ____
PSI per minute with the engine off and the brakes released. - ANSWER: 2
An alcohol evaporator does what? - ANSWER: Reduces the risk of ice in the air brake
valves in cold weather.
If you must make an emergency stop, you should brake so that you: - ANSWER: Stay
in a straight line and can steer.
