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New Jersey CDL DMV Air Brakes 1

Take 6 practice tests for CDL is the best way to prepare for your New Jersey DMV exam is by taking our free practice tests. The following question are from real New Jersey 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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Ouch! While you were on a roll there for a few questions, you didn’t pass this time. But I know this test, and I think you’ll pass next time. Really.

1. 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.

2. The application pressure gauge:
Shows how much air pressure is being applied to the brakes.
Shows the temperature of air being used in the braking system.
Shows the pressure of the air coming from the compressor.
Shows the number of times the brakes have been used.

In an air brake system, the application pressure gauge shows how much air pressure is being applied to the brakes. Not all vehicles with an air brake system have this gauge.

3. Most heavy-duty vehicles use:
Mono air brake systems.
Dual air brake systems.
Triple air brake systems.
Quadruple air brake systems.

Most heavy-duty vehicles use dual air brake systems. A dual system has two separate air brake systems with a single set of controls.

4. Which of the following is not a part of an air brake system?
A service brake system
A parking brake system
An emergency brake system
An axle brake system

Air brakes consists of three separate braking systems: the service brake system, the parking brake system, and the emergency brake system.

5. 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.

6. An air brake-equipped vehicle traveling at a speed of 55 mph under ideal driving conditions will need approximately ____ to come to a complete stop.
100 feet
250 feet
300 feet
450 feet

A vehicle's total stopping distance is made up of perception distance, reaction distance, brake lag distance, and braking distance. With all of these factors included, an air brake-equipped vehicle traveling at a speed of 55 mph under ideal driving conditions will need approximately 450 feet to come to a complete stop.

7. 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.

8. Pressing and releasing the brake pedal unnecessarily can:
Release air faster than it can be replaced.
Add more air to a brake system.
Make the brake pedal harder to depress.
Create a loud noise.

On a vehicle with air brakes, pressing and releasing the brake pedal unnecessarily may let air out of the braking system faster than the compressor can replace it. This may cause the system's air pressure to become too low and the brakes to stop working.

9. 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.

10. If your tractor is equipped with ABS but your trailer is not, the ABS:
Will not be effective.
Will still improve your steering control.
Will make jackknifing easier.
Will allow others to see when you brake.

In a tractor-trailer combination, if the tractor is equipped with an Anti-Lock Braking System (ABS) but the trailer is not, the ABS will still improve the driver's steering control. The driver should keep an eye on the trailer and let up on the brakes if the trailer begins to swing out.

11. When traveling down a steep downgrade:
The air brakes should be used.
Shift into a lower gear, then use brakes to supplement the braking effect of the engine.
The vehicle should be continually downshifted in the place of using the brakes.
The vehicle should be driven on the shoulder.

On a downgrade, the braking effect of the engine should be your primary method of controlling speed. Shift down to a lower gear before starting down the hill and save the brakes for additional slowing or stopping that may be required by road or traffic conditions.

12. To make a stop in a vehicle using air brakes, the driver should:
Press down the brake pedal.
Lift the brake pedal toward them.
Push in the brake knob.
Pull out the brake knob.

To make a normal stop in an air-braked vehicle, push the brake pedal down and control the pressure so that the vehicle comes to a smooth, safe stop.

13. The air pressure in a dual air brake system should build from 85 to 100 psi within:
Two minutes.
15 seconds.
10 minutes.
45 seconds.

When inspecting a vehicle with a dual air brake system, you should wait for air pressure to build from 85 to 100 psi in both the primary and secondary systems. This should take about 45 seconds.

14. Both systems in a dual air brake systems share:
Air tanks.
Hoses.
Air lines.
An air compressor.

Both systems in a dual air brake system share a single air compressor. If the air compressor is damaged, neither system will be able to operate properly.

15. On trucks and buses, where are ABS malfunction lamps located?
On the driver’s door
On the instrument panel
On the outside of the vehicle by the passenger’s door
Under the hood

Tractors, trucks, and buses with Anti-Lock Braking Systems (ABS) have yellow malfunction lamps located on their instrument panels. Trailers have yellow ABS malfunction lamps on their left side, either on the front or rear corner.

16. Air brakes are:
An effective tool for stopping large vehicles.
Prohibited on large vehicles.
Only effective in poor weather.
A tool to improve fuel efficiency.

As long as the brakes are properly maintained, using air brakes is a safe and effective method of stopping large, heavy vehicles.

17. A tank endorsement is:
Only required when transporting gases.
Only required when transporting liquids.
Used when transporting both liquids and gases.
Optional when transporting hazardous materials.

In general, a tank endorsement is required to a drive tank vehicle used to transport liquids or gases. This applies to both hazardous and non-hazardous materials.

18. A dual air brake system:
Has a single air brake system, but uses two sets of controls.
Has one air brake system for each side of the truck.
Has two brakes for each wheel.
Has two separate air brake systems, but uses a single set of controls.

A dual air brake system has two separate air brake systems that use a single set of brake controls. One system typically operates the regular brakes on the rear axle or axles. The other system operates the regular brakes on the front axle.

19. During an applied leakage test, the maximum leakage rate for a double combination vehicle is:
10 psi in a minute.
8 psi in a minute.
6 psi in a minute.
4 psi in a minute.

It is important to know the maximum air loss rate that is safe for your specific vehicle. A double combination vehicle should have a leakage rate no higher than 4 psi in a minute during an applied leakage test.

20. Using an Anti-Lock Braking System (ABS):
Shortens stopping distance.
Shortens brake response time.
Provides less control.
Provides more control.

An Anti-Lock Braking System (ABS) helps prevent wheel lockup during hard braking. While it provides better control, it does not necessarily shorten a vehicle's stopping distance.

21. Front brake limiting valves were intended to:
Prevent the front tires from skidding.
Prevent the front tires from overheating.
Create equal brake usage.
Remove uncertainty when applying the brakes.

Some older vehicles with air brakes have front brake limiting valves. These valves were intended to reduce the risk of front wheels skidding. However, research has shown that such devices are unnecessary, so they should be left in the "normal" position.

22. Emergency brakes are:
Not required on trucks.
Only required on trailers.
Required on tractors.
Only required when transporting hazardous materials.

All trucks, truck tractors, and buses must be equipped with emergency brakes and parking brakes.

23. Which part of the truck is the air compressor connected to?
The transmission
The engine
The radiator
The door latch

In an air brake system, the air compressor is connected to the engine through gears or a v-belt.

24. What color are ABS malfunction lamps?
Orange
Yellow
Green
Blue

Vehicles with Anti-Lock Braking Systems (ABS) have yellow malfunction lamps.

25. What is removed when an air tank is drained?
Water and oil
Ammonia
Wood
Chlorine

In an air brake system, the air storage tanks are equipped with drains to allow water and compressor oil to be removed. The water and oil can damage the brakes if left to accumulate in the system.

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