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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 Wisconsin CDL knowledge test. The WI 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 Wisconsin CDL Manual. Take this WI CDL practice test now to prepare for the actual air brakes test!
1.
If your vehicle does not have automatic air tank drains, how often should you drain air tanks to remove moisture and oil?
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Once a week.
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Every 4 hours.
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At least once a month.
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At the end of each working day.
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2.
In newer vehicles with air brakes, you put on the parking brake:
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using a P-shaped, yellow control knob.
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using a diamond-shaped, yellow, push-pull control knob.
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placing the transmission in Park.
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moving the orange push-pull lever to the right.
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3.
When driving on slippery roads, you should NOT:
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go slowly.
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try to anticipate stops early.
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watch far enough ahead to keep a steady speed.
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use the engine brake.
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4.
What should you do to correct a drive-wheel braking skid?
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Fully apply the brakes, turn the steering wheel quickly, push in the clutch, and countersteer.
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Stop braking, turn the steering wheel quickly, push in the clutch, and countersteer.
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Turn in the same direction as the skid.
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None of the above.
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5.
An ABS system:
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keep your wheels from locking when you brake hard.
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helps you avoid skids caused by over braking.
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gives you more control over the vehicle during braking.
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All of the above.
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6.
How do you check that spring brakes come on automatically?
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Continue to step on and off the brake pedal until the air pressure falls to the manufacturer’s specification.
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On single vehicles, continue to step on and off the brake pedal until the parking brake valve pops out.
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On a tractor-trailer combination vehicle, continue to step on and off the brake pedal until the tractor protection valve and the parking brake valve close.
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All of the above.
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7.
With the controlled braking method, you:
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push down on the brake pedal as hard as you can so that the wheels the lock up.
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apply the brakes as hard as you can without locking the wheels.
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apply the brakes all the way and release brakes when the wheels the lock up.
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None of the above.
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8.
Which of the following is NOT correct? An ABS system:
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is a safety anti-skid braking system.
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helps you stop faster.
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helps you avoid wheel lock up.
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reduces the braking pressure to a safe level.
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9.
If your vehicle has an alcohol evaporator, every day during cold weather, you should:
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ensure that compressed air usually has some water and some compressor oil in it.
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fill it up with oil to prevent alcohol from freezing.
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fill it up with oil to prevent the pipes from freezing.
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check the alcohol container and fill up as necessary.
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10.
If air doesn't flow all the way to the back:
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your lower fifth wheel may fall off.
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a rollover is more likely.
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your brakes will not work properly.
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the trailer will tend to swing around.
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