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