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The air brakes endorsement applies to applicants who wish to drive a vehicle with air brakes in Class A, B, or C CDL. To drive a vehicle with air brakes, you must pass the air brake component of the Oregon CDL knowledge test. The OR CDL air brakes test consists of 25 questions, and you'll need at least 20 correct answers to pass (80%). The test covers the information found in the air brakes section of the Oregon CDL Manual. Take this OR CDL practice test now to prepare for the actual air brakes test!
1.
Most heavy-duty vehicles use:
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solid brakes.
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pressure brakes.
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hydraulic brakes.
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air brakes.
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2.
Why must air tanks be drained?
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Water can freeze in cold weather and cause brake failure.
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To keep from fouling the air compressor oil.
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Water and
oil reduce the air pressure.
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The low boiling point of water reduces braking power.
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3.
Which of the following can cause brakes to fade or fail?
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Brakes out of adjustment
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Excessive use of the service brakes
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Not relying on the engine braking effect
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All of the above.
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4.
During a trip you should check:
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temperature gauges.
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mirrors.
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pressure gauges.
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All of the above.
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5.
One way to prevent hydroplaning is to:
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make sure you have enough tread on your tires.
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take curves at higher speeds.
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have less than 4/32 inch tread depth in every major groove on front tires.
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use the controlled braking method.
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