TEXAS CDL AIR BRAKES QUESTIONS
& SOLUTIONS
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.
To check the free play of manual slack adjusters on s-can brakes you should: -
ANSWER Park on a level ground, chock wheels, and release parking brake.
If the air compressor should develop a leak, what keeps the air in the tanks? - ANSWER
The one way check valve.
When driving down a long steep hill you should: - ANSWER Release the brake when
you are 5 mph below you safe speed.
The brake system that applies and releases the brakes when a driver uses the brake
pedal is the: - ANSWER Service brake system.
& SOLUTIONS
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.
To check the free play of manual slack adjusters on s-can brakes you should: -
ANSWER Park on a level ground, chock wheels, and release parking brake.
If the air compressor should develop a leak, what keeps the air in the tanks? - ANSWER
The one way check valve.
When driving down a long steep hill you should: - ANSWER Release the brake when
you are 5 mph below you safe speed.
The brake system that applies and releases the brakes when a driver uses the brake
pedal is the: - ANSWER Service brake system.
