In Partnership with Karl Junginger Memorial Public Library

View instructions
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. Which of the following is a reason why air tanks must be drained?
Your battery fluid may drain out.
Your brakes may fail due to the water freezing.
The governor may stop the compressor from pumping air.
Your transmission fluid may drain out.
2. Slack adjusters:
regulate the distance that the air brake has to travel to apply friction to the wheel.
are available in four types: manual, automatic, robotic and analog.
should move more than one inch where the push rods attach to them.
regulate the distance between the rear wheels.
3. Under a pressurized system, the radiator cap:
should never be hot.
should be removed when the coolant is hot.
should never be removed until the system has cooled.
should always be cool.
4. Your mirrors should be adjusted so that:
no part of the vehicle is visible in the mirror.
more than half of the mirror shows the vehicle.
a part of the vehicle is visible in the mirror.
the rear of the vehicle is visible in the mirror.
5. When driving in hot weather, drivers should inspect tires:
every 3 hours or every 75 miles.
every hour or every 50 miles.
every 4 hours or every 200 miles.
every 2 hours or every 100 miles.
6. The __________ keeps air from going out if the air compressor develops a leak.
tractor protection valve
one-way check valve
emergency relay valve
air compressor drive belt
7. If air pressure does not build up fast enough:
you should put the parking brake on and gently pull against it in a low gear.
you may be forced to turn off the engine and release the parking brake.
the pressure may drop too low during driving.
you should turn the electrical power on and step on and off the brake pedal.
8. When a tire fails, you must:
stay off the brake.
hold the steering wheel firmly.
get out and check all the tires after you have come to a stop.
All of the above.
9. Excessive use of the service brakes results in overheating. Too much heat can:
cause the brakes to grab.
cause the brakes apply unevenly.
make the brakes stop working.
cause the brakes to squeak.
10. When is it safe to leave your vehicle unattended without applying the parking brakes or chocking the wheels?
When you are conducting your pre-trip inspection.
Only while you are taking a rest break.
When the tank pressure falls to the "cut-in" pressure.
Never.
 
Page 1 of 3
Next page

WI CDL Air Brakes Test

Number of questions: 25
Correct answers to pass:20
Passing score:80%
Share This Online CDL Test
Rate this CDL Air Brakes Test
4.6 out of 5
based on 2602 votes