Iowa CDL Air Brakes 2 - DMV Written Test Questions with Answers - MCQGeeks.com

Q.1

If you are driving and the ABS light comes on, it means that the ABS:

Cannot work due to weather conditions.
Has just been activated.
Is not working properly.

Q.2

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.

Q.3

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.4

How much distance will an air brake-equipped vehicle need to come to a complete stop if it is traveling at 55 mph under ideal driving conditions?

300 feet
100 feet
450 feet

Q.5

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.6

Brakes out of adjustment will:

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

Q.7

The rods in S-cam brakes move the slack adjusters when air pressure is added to the brake chambers. This air pressure is added to the chambers when the driver:

Presses the brake pedal.
Uses the emergency brake.
Uses the trailer hand valve.

Q.8

What do air brakes use to make the brakes work?

Compressed air
Outside air
Non-compressed air

Q.9

If the safety relief valve in an air brake system is releasing air:

You should not be concerned as this is a normal process.
There is something wrong with the brakes.
The valve is operational.

Q.10

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.11

Do not operate a vehicle if any brake drums have cracks that are larger than ____ of the width of the friction area.

One half
One third
One fifth

Q.12

Foundation brakes are used:

Only on the front wheels of a vehicle.
Only on the rear wheels of a vehicle.
On each wheel of a vehicle.

Q.13

While driving, ____ generally holds spring brakes in place.

Air pressure
Electricity
Gasoline

Q.14

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.15

Having ABS on only one axle:

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

Q.16

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.17

During an inspection, slack adjusters on S-cam brakes should not move more than:

One foot.
One centimeter.
One inch.

Q.18

Some air brake systems introduce alcohol into the system to:

Make the brakes work without squeaking.
Prevent ice from forming in the brake system.
Prevent people from breathing the air from the system.

Q.19

A wig wag is:

A low pressure warning device.
A tube that carries air to the brakes.
A type of air brake system.

Q.20

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.

Q.21

Air storage tanks:

Are not allowed on a vehicle.
Hold compressed air for the brakes.
Should be drained of excess air after every trip.

Q.22

What tells you how much pressure is in your vehicle's air tanks?

The supply pressure gauge
The ABS malfunction lamp
The tractor protection valve

Q.23

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.24

What color light indicates a vehicle's ABS is not working?

Green
Blue
Yellow

Q.25

An application pressure gauge shows:

How much air pressure is being applied to the brakes.
How much air pressure is available.
How much air pressure is required to stop a vehicle.

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