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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 Wyoming CDL knowledge test. The WY 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 Wyoming CDL Manual. Take this WY CDL practice test now to prepare for the actual air brakes test!
1. The air brake lag distance at 55 mph on dry pavement adds about:
16 feet.
32 feet.
60 feet.
75 feet.
2. When driving on long and/or steep downgrades, to select an appropriate safe speed you should consider:
the length of the grade.
the road conditions.
the total weight of the vehicle and cargo.
All of the above.
3. If a vehicle is equipped with ABS, when you start the engine:
the ABS indicator light on the dash should come on and then turn off.
the trailer emergency brakes will come on.
the wheels will lock up.
the spring brakes will come on.
4. The braking power of the spring brakes:
depends on the brakes being in adjustment.
is not affected by the condition of the service brakes.
is not affected by the air pressure level.
All of the above.
5. A broken exhaust system:
poses no threat to the driver.
can improve fuel efficiency.
can let poisonous carbon monoxide to leak into the cab.
does not cause problems.
6. Emergency brakes are:
not required on commercial vehicles with air brakes.
not required on buses.
not required on doubles.
required on all vehicles.
7. If air doesn't flow all the way to the back:
your lower fifth wheel may fall off.
a rollover is more likely.
the trailer will tend to swing around.
your brakes will not work properly.
8. What is the best way to test the low air pressure warning signal?
step on and off the brake pedal while the engine is running.
pump the brakes until the air pressure drops below 45 psi.
Shut the engine off when you have enough air pressure, turn the electrical power on and step on and off the brake pedal to reduce air pressure to below 60 psi.
All of the above.
9. Before leaving your vehicle unattended, you should:
Remove the keys.
Chock the wheels.
Apply the parking brake.
All of the above.
10. Brake drums or discs must not have cracks longer than ____ the width of the friction area.
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WY CDL Air Brakes Test

Number of questions: 25
Correct answers to pass:20
Passing score:80%
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