Iowa CDL Air Brakes 1 - DMV Written Test Questions with Answers - MCQGeeks.com

Q.1

Why do large vehicles use air brakes?

Other brake systems squeak too loudly.
Air brakes are very effective systems.
Other braking systems are hard to come by.

Q.2

If using spring brakes when hauling a heavy load, a complete stop will:

Be impossible.
Take a long time.
Take a short amount of time.

Q.3

Brake fade is a result of:

Brakes being exposed to sunlight.
Brakes being exposed to moisture.
Excessive use of the brakes.

Q.4

When leaving a vehicle unattended, a driver should:

Always set the parking brake.
Only set the parking brake if the vehicle is parked on a slope.
Deflate the tires by 10 percent.

Q.5

If the spring brakes are on, you should:

Not use the brake pedal.
Press the accelerator.
Move the steering wheel.

Q.6

In a vehicle with dual parking control valves, a separate air tank can be used:

To make the air brakes work more effectively.
To temporarily release the spring brakes.
To charge the brakes on the rear trailer.

Q.7

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.

Q.8

Anti-Lock Braking Systems (ABS):

Reduce a vehicle's normal braking capacity.
Are in addition to other braking systems and do not reduce a vehicle's braking power.
Are not effective on larger vehicles.

Q.9

A ____ allows a driver to gradually apply spring brakes.

Modulating control valve
Trailer air supply control
Relay valve

Q.10

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.11

To affect a vehicle, ABS:

Must be on all axles.
Must be on the rear axle.
Can be on as few as one axle.

Q.12

An Anti-Lock Braking System (ABS):

Is not available for vehicles with air brakes.
Is not helpful in most driving situations.
Can help you maintain control when braking.

Q.13

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.14

In a dual air brake system:

Air tanks are shared between both systems.
Each system has its own air tanks.
You must designate which system you are using.

Q.15

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.16

Brakes out of adjustment will:

Work properly.
Cause some of the brakes to overwork and malfunction.
Allow better acceleration.

Q.17

A driver can rely on front wheel braking to work:

On dry roadways only.
Under all conditions.
Under all conditions, except for snow.

Q.18

The leakage rate for a triple combination vehicle with air brakes should be no more than ____ in one minute during a static leakage test.

8 psi
5 psi
3 psi

Q.19

What is removed when an air tank is drained?

Water and oil
Ammonia
Liquid cleaners

Q.20

What do the two systems of a dual air brake system share?

Hoses
An air compressor
Air tanks

Q.21

Using the brakes creates heat. If too much heat is produced:

The brakes may not work.
The brakes may squeak more than usual.
The brakes will brake unevenly.

Q.22

The ____ are activated by an electric switch that is triggered by the brake pedal.

Headlights
Turn signals
Brake lights

Q.23

Having ABS on only one axle:

Can be dangerous.
Still allows you additional control when braking.
Slows the vehicle, but cannot stop it.

Q.24

Air tank drains:

Should not be used in cold weather.
Are helpful to remove water and oil from the air tanks.
Are used to move air to the brakes.

Q.25

A dual air brake system:

Consists of two separate air brake systems that share a single set of controls.
Is a single air brake system with two different sets of controls.
Consists of one air brake system for the left side of the truck and one system for the right side of the truck, each with its own set of controls.

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