The time required for the brakes to work after the brake pedal is pushed

The distance between the brake pedal’s resting position and the floor

The amount of air pressure used to stop a vehicle

New Hampshire CDL Air Brakes 1 - DMV Written Test Questions with Answers

Q.1

Air brakes use ____ to function.

Compressed air
Liquid air
Nitrogen

Q.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.

Q.3

When about to drive a vehicle with a dual brake system, a driver should:

Let the vehicle warm up to ensure the fuel reaches the engine.
Wait for air pressure to build in both the primary and secondary systems.
Begin driving just after the engine starts.
Pump the pedal about 20 times to build pressure, then begin driving.

Q.4

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.

Q.5

You should test the low pressure warning signal by:

Turning on the engine and applying the trailer hand brake.
Rapidly pressing and releasing the brake pedal.
Removing wheel chocks and disengaging the parking brake.

Q.6

To use the stab braking method, you should:

Apply the brakes completely until the wheels lock up, release the brakes until the wheels start rolling, then repeat the process.
Apply the brakes about halfway, but allow the wheels to keep rolling.
Apply the brakes completely until the wheels lock up and the vehicle stops.
Apply the emergency brake until the vehicle starts to slow.

Q.7

Truck tractors with air brakes that were built on or after March 1, 1997 are equipped with:

An extra set of brakes.
Voice-activated brakes.
Cruise control.
Anti-Lock Braking Systems (ABS).

Q.8

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.

Q.9

When an S-cam turns inside a brake drum, the S-cam:

Presses the brake shoes against the inside of the brake drum.
Presses the brake shoes against the brake linings.
Presses the brake linings against the wheel axles.

Q.10

Emergency brakes:

Are not required on trucks.
Are only required on trailers.
Are required on tractors.
Are optional.

Q.11

A ____ allows a driver to gradually apply spring brakes.

Modulating control valve
Trailer air supply control
Relay valve

Q.12

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.

Q.13

Dollies equipped with ABS are required to have malfunction lamps located where?

On the rear
On the left side
On the front
On the top

Q.14

What is brake lag?

The time required for the brakes to work after the brake pedal is pushed
The distance between the brake pedal’s resting position and the floor
The amount of air pressure used to stop a vehicle
How faded the brakes are

Q.15

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

Q.16

To make a stop in a vehicle equipped with air brakes, the driver should:

Press the brake pedal down.
Lift the brake pedal up.
Pull out the air brake knob.

Q.17

Brakes can get out of adjustment:

If they are hot.
During the winter.
If they are used at all.
If brakes on one side are used more often than brakes on the other side.

Q.18

Most heavy-duty vehicles use:

Single air brake systems.
Dual air brake systems.
Triple air brake systems.
Quadruple air brake systems.

Q.19

Once the air tanks are at an air pressure level of 125 psi, the air compressor governor will:

Stop the compressor from pumping air.
Release air from the tanks.
Begin pumping air into the tanks.

Q.20

When leaving your vehicle unattended:

The parking brake should be used.
The parking brake only needs to be used if the vehicle is parked on a slope.
The parking brake should not be used, as it can damage the tires.

Q.21

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.

Q.22

The parking brake should be:

Used whenever you park the vehicle.
Used while driving.
Set when driving in bad weather.
Used to stop the vehicle in normal driving.

Q.23

A low air pressure warning signal:

Is not required on vehicles with air brakes.
Is required on vehicles with air brakes.
Is optional on vehicles with air brakes.

Q.24

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.

Q.25

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.