CDL Air Brake Practice Test Questions with Verified
Answers Graded A+
The parking or emergency brake on a heavy and sits at the bottom.
vehicle can only be held in position by something b. Eliminate the need for daily tank draining.
that cannot leak away, like: c. Boost tank pressure the same way that
superchargers boost engines.
a. Fluid pressure d. Reduce the risk of ice in the air brake valves in
b. Spring pressure cold weather. - ANSWER -d. Reduce the
c. Air pressure risk of ice in the air brake valves in cold weather.
d. Any of the above - ANSWER -b. Spring
pressure
Air braking takes more time than hydraulic
because air:
A straight truck or bus air brake system should
not leak at a rate of more than __ psi per minute a. Brakes use different brake drums.
with the engine off and the brake released. b. Takes more time to flow through the lines than
hydraulic fluid.
a. 1 c. Brakes require heavier return springs.
b. 2 d. Is always leaking through airline fittings. -
c. 3 ANSWER -b. Takes more time to flow
d. 4 - ANSWER -c. 3 through the lines than hydraulic fluid.
Your vehicle has dual air brake system. If low air The brake pedal in an air brake system:
pressure warning comes on for the secondary
system or for one system, you should: a. Controls the speed of the air compressor.
b. Always needs to be held down halfway during
a. Bring the vehicle to a safe stop and continue normal driving.
only when the system is fixed. c. Controls the air pressure applied to put on the
b. Reduce your speed, and test the remaining brakes.
system while under-way. d. Is connected to slack adjusters by a series of
c. Reduce your speed, and drive to the nearest rods and linkages. - ANSWER -c. Controls
garage for repairs. the air pressure applied to put on the brakes.
d. Continue at normal speed if only the
secondary system fails. - ANSWER -a.
Bring the vehicle to a safe stop and continue only
when the system is fixed. With air brake vehicles, the parking brakes
should be used:
a. Whenever you leave the vehicle unattended.
If your vehicle has an alcohol evaporator, it is b. To hold your speed when going downhill.
there to: c. As little as possible.
d. Only during pre and post-trip inspections. -
a. Rid the wet tank of alcohol that condenses ANSWER -a. Whenever you leave the
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, CDL Air Brake Practice Test Questions with Verified
Answers Graded A+
vehicle unattended. b. Foot
c. S-cam
d. Drum - ANSWER -a. Emergency
For emergency stab braking, you should:
a. Pump the brake pedal rapidly and lightly. To check the free play of the manual slack
b. Press on the brake pedal as hard as you can, adjusters on the S-cam brakes, you should park
release the brakes when the wheels lock, and on:
when the wheels start rolling put on the brakes
fully again. a. Level ground with the parking brake on, then
c. Brake hard until the wheels lock, then get off apply the service brake.
the brakes for as much time as the wheels were b. Level ground, chock the wheels, and turn off
locked. the parking brakes.
d. Press hard on the brake pedal and apply full c. Level ground and drain off air pressure before
hand valve until you stop. - ANSWER -b. adjusting.
Press on the brake pedal as hard as you can, d. A slight grade, release the parking brake,
release the brakes when the wheels lock, and apply the service brake and check for vehicle
when the wheels start rolling put on the brakes movement. - ANSWER -b. Level ground,
fully again. chock the wheels, and turn off the parking
brakes.
If your truck or bus has dual parking control
valves, you can use pressure from a separate Of the choices below, the first thing to do when a
tank to: low air pressure warning comes on is:
a. Release the spring emergency/ parking brakes a. Stop and safely park as soon as possible.
to move a short distance. b. Shift to next higher gear.
b. Apply more brake pressure if the main tank is c. Adjust the brake pedal for more travel.
getting low. d. Open the air supply control valve. -
c. Stay parked twice as long with your service air ANSWER -a. Stop and safely park as soon
pressure. as possible.
d. Balance the service brake system whenever
you are parked. - ANSWER -a. Release the
spring emergency/ parking brakes to move a
short distance. The air compressor governor controls:
a. The speed of the air compressor.
b. When the brake chambers release pressure.
Modern air brakes systems combine three c. Air pressure is applied to the brakes.
different systems. They are the service, parking, d. When air is pumped into the air tanks. -
and the _________ brakes. ANSWER -d. When air is pumped into the
air tanks.
a. Emergency
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Answers Graded A+
The parking or emergency brake on a heavy and sits at the bottom.
vehicle can only be held in position by something b. Eliminate the need for daily tank draining.
that cannot leak away, like: c. Boost tank pressure the same way that
superchargers boost engines.
a. Fluid pressure d. Reduce the risk of ice in the air brake valves in
b. Spring pressure cold weather. - ANSWER -d. Reduce the
c. Air pressure risk of ice in the air brake valves in cold weather.
d. Any of the above - ANSWER -b. Spring
pressure
Air braking takes more time than hydraulic
because air:
A straight truck or bus air brake system should
not leak at a rate of more than __ psi per minute a. Brakes use different brake drums.
with the engine off and the brake released. b. Takes more time to flow through the lines than
hydraulic fluid.
a. 1 c. Brakes require heavier return springs.
b. 2 d. Is always leaking through airline fittings. -
c. 3 ANSWER -b. Takes more time to flow
d. 4 - ANSWER -c. 3 through the lines than hydraulic fluid.
Your vehicle has dual air brake system. If low air The brake pedal in an air brake system:
pressure warning comes on for the secondary
system or for one system, you should: a. Controls the speed of the air compressor.
b. Always needs to be held down halfway during
a. Bring the vehicle to a safe stop and continue normal driving.
only when the system is fixed. c. Controls the air pressure applied to put on the
b. Reduce your speed, and test the remaining brakes.
system while under-way. d. Is connected to slack adjusters by a series of
c. Reduce your speed, and drive to the nearest rods and linkages. - ANSWER -c. Controls
garage for repairs. the air pressure applied to put on the brakes.
d. Continue at normal speed if only the
secondary system fails. - ANSWER -a.
Bring the vehicle to a safe stop and continue only
when the system is fixed. With air brake vehicles, the parking brakes
should be used:
a. Whenever you leave the vehicle unattended.
If your vehicle has an alcohol evaporator, it is b. To hold your speed when going downhill.
there to: c. As little as possible.
d. Only during pre and post-trip inspections. -
a. Rid the wet tank of alcohol that condenses ANSWER -a. Whenever you leave the
1/5
, CDL Air Brake Practice Test Questions with Verified
Answers Graded A+
vehicle unattended. b. Foot
c. S-cam
d. Drum - ANSWER -a. Emergency
For emergency stab braking, you should:
a. Pump the brake pedal rapidly and lightly. To check the free play of the manual slack
b. Press on the brake pedal as hard as you can, adjusters on the S-cam brakes, you should park
release the brakes when the wheels lock, and on:
when the wheels start rolling put on the brakes
fully again. a. Level ground with the parking brake on, then
c. Brake hard until the wheels lock, then get off apply the service brake.
the brakes for as much time as the wheels were b. Level ground, chock the wheels, and turn off
locked. the parking brakes.
d. Press hard on the brake pedal and apply full c. Level ground and drain off air pressure before
hand valve until you stop. - ANSWER -b. adjusting.
Press on the brake pedal as hard as you can, d. A slight grade, release the parking brake,
release the brakes when the wheels lock, and apply the service brake and check for vehicle
when the wheels start rolling put on the brakes movement. - ANSWER -b. Level ground,
fully again. chock the wheels, and turn off the parking
brakes.
If your truck or bus has dual parking control
valves, you can use pressure from a separate Of the choices below, the first thing to do when a
tank to: low air pressure warning comes on is:
a. Release the spring emergency/ parking brakes a. Stop and safely park as soon as possible.
to move a short distance. b. Shift to next higher gear.
b. Apply more brake pressure if the main tank is c. Adjust the brake pedal for more travel.
getting low. d. Open the air supply control valve. -
c. Stay parked twice as long with your service air ANSWER -a. Stop and safely park as soon
pressure. as possible.
d. Balance the service brake system whenever
you are parked. - ANSWER -a. Release the
spring emergency/ parking brakes to move a
short distance. The air compressor governor controls:
a. The speed of the air compressor.
b. When the brake chambers release pressure.
Modern air brakes systems combine three c. Air pressure is applied to the brakes.
different systems. They are the service, parking, d. When air is pumped into the air tanks. -
and the _________ brakes. ANSWER -d. When air is pumped into the
air tanks.
a. Emergency
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