CDL Air Brake Practice Test Exam Review Questions and Answers 100% Correct
1. The parking or emergency brake on a heavy vehicle can only be held in position b
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y something that cannot leak away, like:
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a. Fluid pressure w
b. Spring pressure w
c. Air pressure w
d. Any of the above: b. Spring pressure
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2. A straight truck or bus air brake system should not leak at a rate of more than
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psi per minute with the engine off and the brake released.
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a. 1
b. 2
c. 3
d. 4: c. 3 w w
3. Your vehicle has dual air brake system. If low air pressure warning comes on for the
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secondary system or for one system, you should:
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a. Bring the vehicle to a safe stop and continue only when the system is fixed.
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b. Reduce your speed, and test the remaining system while under-way.
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c. Reduce your speed, and drive to the nearest garage for repairs.
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d. Continue at normal speed if only the secondary system fails.: a. Bring the vehicle to
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a safe stop and continue only when the system is fixed.
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4. If your vehicle has an alcohol evaporator, it is there to:
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a. Rid the wet tank of alcohol that condenses and sits at the bottom.
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b. Eliminate the need for daily tank draining. w w w w w w
c. Boost tank pressure the same way that superchargers boost engines.
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d. Reduce the risk of ice in the air brake valves in cold weather.: d. Reduce the risk of ice
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in the air brake valves in cold weather.
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11
, 5. Air braking takes more time than hydraulic because air:
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a. Brakes use different brake drums.
w w w w
b. Takes more time to flow through the lines than hydraulic fluid.
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c. Brakes require heavier return springs.
w w w w
d. Is always leaking through airline fittings.: b. Takes more time to flow through the lines
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than hydraulic fluid.
w w
6. The brake pedal in an air brake system:
w w w w w w w
a. Controls the speed of the air compressor.
w w w w w w
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11
1. The parking or emergency brake on a heavy vehicle can only be held in position b
w w w w w w w w w w w w w w w
y something that cannot leak away, like:
w w w w w w
a. Fluid pressure w
b. Spring pressure w
c. Air pressure w
d. Any of the above: b. Spring pressure
w w w w w w
2. A straight truck or bus air brake system should not leak at a rate of more than
w w w w w w w w w w w w w w w w w
psi per minute with the engine off and the brake released.
w w w w w w w w w w
a. 1
b. 2
c. 3
d. 4: c. 3 w w
3. Your vehicle has dual air brake system. If low air pressure warning comes on for the
w w w w w w w w w w w w w w w
secondary system or for one system, you should:
w w w w w w w w
a. Bring the vehicle to a safe stop and continue only when the system is fixed.
w w w w w w w w w w w w w w
b. Reduce your speed, and test the remaining system while under-way.
w w w w w w w w w
c. Reduce your speed, and drive to the nearest garage for repairs.
w w w w w w w w w w
d. Continue at normal speed if only the secondary system fails.: a. Bring the vehicle to
w w w w w w w w w w w w w w
a safe stop and continue only when the system is fixed.
w w w w w w w w w w w
4. If your vehicle has an alcohol evaporator, it is there to:
w w w w w w w w w w
a. Rid the wet tank of alcohol that condenses and sits at the bottom.
w w w w w w w w w w w w
b. Eliminate the need for daily tank draining. w w w w w w
c. Boost tank pressure the same way that superchargers boost engines.
w w w w w w w w w
d. Reduce the risk of ice in the air brake valves in cold weather.: d. Reduce the risk of ice
w w w w w w w w w w w w w w w w w w
in the air brake valves in cold weather.
w w w w w w w w
1w/w
11
, 5. Air braking takes more time than hydraulic because air:
w w w w w w w w
a. Brakes use different brake drums.
w w w w
b. Takes more time to flow through the lines than hydraulic fluid.
w w w w w w w w w w
c. Brakes require heavier return springs.
w w w w
d. Is always leaking through airline fittings.: b. Takes more time to flow through the lines
w w w w w w w w w w w w w w w
than hydraulic fluid.
w w
6. The brake pedal in an air brake system:
w w w w w w w
a. Controls the speed of the air compressor.
w w w w w w
2w/w
11
