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

Oregon CDL Air Brakes 2 - DMV Written Test Questions with Answers

Q.1

How many air storage tanks are used in an air brake system?

Two tanks
Four tanks
Six tanks
The number varies.

Q.2

Most heavy-duty vehicles use ____ air brake systems.

Single
Dual
Triple
Quad

Q.3

All air tanks must include:

A drain valve.
A lock.
A trap door.
A warning sticker.

Q.4

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.5

Most heavy-duty vehicles use:

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

Q.6

To stop a vehicle using air brakes:

The brake pedal should be pressed.
The brake pedal should be lifted.
The brake knob should be pulled out.
The brake knob should be pushed in.

Q.7

What should happen before the air pressure in an air brake system tank falls below 55 psi?

The warning light should activate.
The vehicle will be unable to shift out of gear.
The front lights should flash.

Q.8

Why do large vehicles use air brakes?

Other brake systems squeak too loudly.
Air braking systems are very effective.
Air brakes are complicated.
Air is free.

Q.9

Failing to drain air tanks could result in:

Water accumulations freezing and causing brake failure.
Squishy brakes.
Too much air collecting in the tanks.

Q.10

____ make up the emergency brake system.

Only parts of the parking brake system
Only parts of the service brake system
Parts of the parking and service brake systems

Q.11

Foundation brakes are used:

Only at the front wheels.
Only at the rear wheels.
Only at the driver’s side wheels.
At each wheel.

Q.12

Using an Anti-Lock Braking System (ABS):

Shortens stopping distance.
Shortens brake response time.
Provides less control.
Provides more control.

Q.13

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.14

What is removed when an air tank is drained?

Water and oil
Ammonia
Wood
Chlorine

Q.15

Why should you regularly drain the air tanks?

Because the air gets old and needs to be replaced
Because compressed air contains some water and the water collects in the tanks
To allow for a change in pressure

Q.16

If the low air pressure warning signal comes on, you should:

Continue driving, but have the brakes repaired within a week.
Pull over and inspect the brakes.
Phone a mechanic while driving.

Q.17

Air tank drains should:

Not be used by the driver.
Only be used when it is wet outside.
Be used to drain the tanks completely.

Q.18

A ____ allows a driver to gradually apply spring brakes.

Modulating control valve
Trailer air supply control
Relay valve

Q.19

What kind of force do emergency brakes use?

Air pressure
Mechanical
Heavy

Q.20

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.

Q.21

A safety valve is set to open at ____ pounds per square inch (psi).

Q.22

If you are braking on dry pavement while traveling at 55 mph, how much distance will brake lag add to your overall stopping distance?

32 feet
45 feet
20 feet

Q.23

Brakes may get out of adjustment:

If they are too hot.
In colder weather.
If they are used.
If they get wet.

Q.24

What do air brakes use to make the brakes work?

Compressed air
Outside air
Non-compressed air

Q.25

An emergency brake must be controlled by:

Mechanical force.
Air pressure.
Gravity.