AIR BRAKES PRACTICE TEST - VIRGINIA
21.
Air brakes use ________ to make the brakes work.
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compressed gas cylinders
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compressed air
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compressed gases
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22.
The stop light switch:
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turns on the brake lights when you put on the air brakes.
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warns you when the air supply pressure drops below 55 psi.
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tells you when you need to use your parking brake instead of the service brake.
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23.
In vehicles with air brakes, the two markings on a front brake limiting valve are:
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left and right.
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normal and slippery.
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high and low.
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24.
In air-operated disc brakes, the pressure of the ______ on the ______ turns a "power screw".
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brake chamber; slack adjuster
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slack adjuster; tie rod
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brake camshaft; tie rod
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25.
Most hydraulic brake failures occur for one of two reasons, one of which is:
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excessive downshifting.
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loss of hydraulic pressure.
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relying too much on the engine braking effect.
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