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Wyoming CDL DMV Air Brakes 2

Take 6 practice tests for CDL is the best way to prepare for your Wyoming DMV exam is by taking our free practice tests. The following question are from real Wyoming DMV practice test. More than 95% people pass a DMV exam when practice at DMV Practice Test.

Number of Test
6
Number of Question
25
Passing score
20
13%
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  • 0Incorrect
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1. The air compressor governor controls:
When the air compressor pumps air into the air storage tanks.
How fast air is pumped into the air storage tanks.
The temperature of air pumped into the air storage tanks.
The speed of the vehicle.

In an air brake system, the air compressor governor controls when the air compressor pumps air into the air storage tanks.

2. Before driving a vehicle with a dual air brake system, you must wait for the air compressor to build a minimum of ____ in both the primary and secondary systems.
25 psi
50 psi
75 psi
100 psi

Before driving a vehicle with a dual air brake system, you should wait for the air compressor to build up at least 100 psi in both the primary and secondary systems.

3. During an applied leakage test, the maximum leakage rate for a single vehicle with air brakes is:
3 psi in one minute.
6 psi in one minute.
8 psi in one minute.
4 psi in one minute.

It is important to know the maximum air loss rate that is safe for your specific vehicle. A single vehicle with air brakes should have a leakage rate no higher than 3 psi in a minute during an applied leakage test.

4. The air entering air storage tanks may contain:
Water and compressor oil.
Frost.
Gravel.
Antifreeze.

The air that enters air storage tanks in an air brake system usually contains a certain amount of water and compressor oil. Because accumulations of these materials can damage the braking system, tanks are equipped with drains to allow their removal.

5. When the brake pedal is depressed, air brakes work:
Immediately.
After a short delay.
After about a minute.
Only if the green lever on the control panel is pushed down.

After the brake pedal is pushed down in a vehicle with air brakes, it takes a half-second or more for air to flow through the lines and make the brakes work. This contrasts with hydraulic brakes used in cars and light and medium trucks, which instantly begin working when the pedal is pushed.

6. During an applied leakage test, what is the maximum leakage rate that is safe for a single vehicle with air brakes?
10 psi in one minute
5 psi in one minute
3 psi in one minute

It is important to know the maximum air loss rate that is safe for your specific vehicle. A single vehicle with air brakes should have a leakage rate no higher than 3 psi in a minute during an applied leakage test.

7. Most heavy-duty vehicles use:
Single air brake systems.
Dual air brake systems.
Triple air brake systems.
Quadruple air brake systems.

Most heavy-duty vehicles use dual air brake systems, in which there are two separate braking systems operated by a single set of controls. Each system operates the brakes on different axles.

8. If the low air pressure warning signal comes on in a vehicle with air brakes, the driver should:
Test the brakes while driving, but continue driving if nothing seems wrong.
Immediately stop driving.
Drive with the hazard lights activated.

If the low air pressure warning signal comes on while you are operating a vehicle with air brakes, you should stop and safely park the vehicle as soon as possible. It is essential that you are able to stop safely while you still have some braking power remaining.

9. When parked on a flat surface, you should:
Use wheel chocks to prevent your vehicle from moving.
Not use wheel chocks.
Use wheel chocks, but only if you have applied the parking brake.

When parking on a level surface, you should use wheel chocks. If the vehicle is not equipped with spring brakes, this is essential to prevent the trailer from moving.

10. You should ____ if the low pressure warning signal activates while you are driving.
Stop where you are and park
Exit the roadway as soon as safely possible
Continue driving normally

If the low pressure warning signal activates while you are driving, it is important that you safely exit the roadway as soon as possible and park your vehicle. If the air pressure gets too low, the brakes will no longer work well enough for you to stop safely.

11. When traveling down a steep downgrade:
The air brakes should be used.
The vehicle should be placed in a low gear and the driver should use engine braking.
The driver should continually downshift instead of using the brakes.

On long and/or steep downgrades, you should primarily use engine braking to control the speed of your vehicle. Use your brakes only as a supplement to this effect.

12. When the spring brakes are activated in a vehicle with air brakes, you should never:
Turn on the lights.
Turn the vehicle off.
Push the brake pedal down.
Open the trailer doors.

In a vehicle with air brakes, never push the brake pedal down when the spring brakes are activated. The combined force of the springs and the pressure of the air brakes could damage the brakes.

13. An air compressor governor will stop the compressor from pumping air once the air tanks have an air pressure level of:
125 psi.
100 psi.
150 psi.
80 psi.

An air compressor governor will stop the compressor from pumping air once the air tanks are at an air pressure level of 125 psi. This air pressure level is referred to as the "cut-out" level.

14. What is removed when an air tank is drained?
Water and oil
Ammonia
Liquid cleaners

In an air brake system, air tanks have drains to remove accumulations of water and compressor oil. Allowing water and oil to accumulate in the system could cause damage to the brakes.

15. The service brake system:
Applies and releases the brakes when you press the brake pedal while driving normally.
Applies and releases the parking brakes.
Applies and releases the emergency brake.
Applies and releases the axle brake.

Air brakes consists of three separate braking systems: the service brake system, the parking brake system, and the emergency brake system. The service brake system applies and releases the brakes when you use the brake pedal while driving normally.

16. If the low pressure warning light comes on while you are driving:
Braking will only be possible if there is still enough air in the tanks.
You can apply the brakes 14 times before the air in the system runs out.
You should continue to drive normally and check the brake system when it is convenient.
You should stay at least 100 feet away from other vehicles.

When driving a vehicle with air brakes, if the low air pressure warning light comes on, it is important for you to stop and safely park your vehicle as soon as possible. There may be a leak in the system. Controlled braking will remain possible only as long as there is enough air left in the tanks.

17. What do air brakes use to make the brakes work?
Compressed air
Outside air
Non-compressed air

Many large CMVs are equipped with air brakes. An air braking system uses compressed air to operate.

18. A low air pressure warning signal should activate:
When tank pressure falls below 120 psi.
When tank pressure falls below 60 psi.
When tank pressure falls below 10 psi.
When tank pressure falls below 5 psi.

In an air brake system, a low air pressure warning signal must come on if air pressure in the tanks falls below 60 psi. This warning signal may come in the form of a light, a buzzer, or a wig wag.

19. Air tank drains:
Allow rain water to enter an air tank.
Are used to drain water and oil from an air tank.
Should never be opened.
Must remain open during driving.

Compressed air in an air brake system usually contains a certain amount of water and compressor oil. The water and oil can damage the brakes if left to accumulate in the system. Manually operated air tank drains must be opened daily to remove this build-up.

20. What do anti-lock brakes do?
Help a driver avoid wheel lockup
Lock up the front wheels
Prevent a vehicle from accelerating while traveling uphill
Prevent a vehicle from accelerating while traveling downhill

The function of an Anti-Lock Braking System (ABS) is to prevent the vehicle's wheels from locking up from hard brake application.

21. Braking mechanisms are located ____ a brake drum.
Outside
Inside
Next to
On top of

Drum brakes are attached to the wheels and located on the axles of a vehicle. The braking mechanisms that cause the vehicle to stop can be found inside of a drum brake.

22. Truck tractors with air brakes built on or after March 1, 1997 must have:
An Anti-Lock Braking System (ABS).
Bluetooth.
GPS.
A rear back-up camera.

Truck tractors with air brakes built on or after March 1, 1997 must be equipped with Anti-Lock Braking Systems (ABS).

23. During a walk-around inspection, ensure there are no cracks on the brake drums that are more than ____ of the width of the friction area.
One half
One quarter
One third
One tenth

Before beginning a trip, it is important to check the brake drums during your walk-around inspection. It is unsafe to drive if any brake drum has a crack more than one half of the width of the friction area.

24. What does the air compressor governor do?
It stops the compressor from pumping air.
It turns on the air compressor.
It stores the compressed air.

In an air brake system, the air compressor governor controls when the air compressor pumps air into the storage tanks. It stops pumping if the pressure in the tanks becomes too high, and begins pumping if the pressure becomes too low.

25. While driving downhill, you should brake until you reach a speed that is ____ below your safe speed, then release the brake pedal.
5 mph
10 mph
15 mph
20 mph

While driving downhill, you should hold down the brake pedal until your vehicle reaches a speed 5 mph below your safe speed, then release the brake pedal. Repeat this process.

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