Air Brake Test

Front 1

The air compressor governor controls:

Back 1

When air is pumped into air tanks.

Front 2

What is emergency stab braking?

Back 2

Brake as hard as you can, release the brakes when the wheels lock, and reapply the brakes again when the wheels start rolling.

Front 3

To check the free play of manual slack adjusters on S-cam brakes, you should park on level ground:

Back 3

Chock the wheels and turn off parking brakes.

Front 4

Which of these is NOT a proper time to apply the parking brakes?

Back 4

When your brakes are very hot.

Front 5

Excessive use of the service brakes results in overheating, which can lead to:

Back 5

Expansion of the brake drums.

Front 6

The driver must be able to see a warning before air pressure in the service air tanks falls below___ psi:

Back 6

55

Front 7

The proper method of braking when going down long and/or steep grades, after selecting the proper gear, is to brake until your speed is about___ miles per hour below your "safe" speed, then release your brakes.

Back 7

5

Front 8

If your truck or bus has dual parking control valves, you can use pressure from a separate tank to:

Back 8

Release spring emergency/parking brakes to move short distance.

Front 9

The brake pedal in an air brake system:

Back 9

Controls the air pressure applied to put on the brakes.

Front 10

If air pressure does NOT build up to normal within the correct amount of time:

Back 10

Your air pressure may drop too low during driving.

Front 11

Under normal conditions, to engage the parking brakes the driver must first:

Back 11

Let the air out of the air brake system

Front 12

Some air brake systems have an alcohol evaporator. What may happen if you don't keep the unit filled with alcohol?

Back 12

Ice may form in the air storage tanks and cause the brakes to fail

Front 13

The parking or emergency brake on a heavy vehicle can only be held in position by something that cannot leak away, like:

Back 13

Spring pressure.

Front 14

How should you check that your service brakes are working properly?

Back 14

Wait for normal air pressure, release the parking brake, move the truck forward slowly, and apply the brake pedal firmly.

Front 15

Total stopping distance for vehicles with air brakes is longer than that for vehicles with hydraulic brakes due to___ distance.

Back 15

Brake lag.

Front 16

Your truck or bus has a dual air brake system. If a low air pressure warning comes on for only one system, what should you do?

Back 16

Stop and safely park. Continue only after the system is fixed.

Front 17

If you must make an emergency stop, you should brake so you:

Back 17

Can steer and your vehicle stays in a straight line.

Front 18

The brake system that applies and releases the brakes when the driver uses the brake pedal is the ___ brake system.

Back 18

Service.

Front 19

The air brake system for a straight truck or bus should not leak at a rate of more than ___ psi per minute with the engine OFF and the brakes released.

Back 19

2

Front 20

Before driving a truck or bus with a dual air brake system, the pressure in each system should be at least ___ psi

Back 20

100

Front 21

In air brake vehicles, the parking brakes should be used:

Back 21

Any time the vehicle is parked.

Front 22

The most common type of foundation brake found on heavy vehicles is the:

Back 22

S-cam drum

Front 23

Repeatedly pressing and releasing (fanning) the brake pedal may result in:

Back 23

The loss of brake air pressure.

Front 24

If the spring brakes are on, when should you push the brake pedal?

Back 24

Never.

Front 25

How should you check that the trailer brakes come on when air pressure in the system drops below a certain level?

Back 25

Chock the wheels, apply the parking brake, shut the engine off, and pump the brake pedal to reduce air tank pressure.

Front 26

You should know your brakes are fading when:

Back 26

You have to push the brake pedal harder to control speed on a downgrade.

Front 27

The air loss rate for a straight truck or bus with the engine off and the brakes on should not be more than:

Back 27

3 psi in one minute.

Front 28

The brake pedal in an air brake system:

Back 28

Controls the air pressure applied to put on the brakes.

Front 29

Truck and bus parking or emergency brakes must be held on by:

Back 29

Mechanical force.

Front 30

The air brake lag distance at 55 mph on dry pavement adds about ___ feet to your stopping distance.

Back 30

32.

Front 31

What is emergency controlled braking?

Back 31

You apply the brakes as hard as you can without locking the wheels.

Front 32

The driver must be able to see a low air pressure warning which comes on before pressure in the service air tanks falls below ___ psi.

Back 32

55

Front 33

For air brake systems in good conditions, the air compressor should start pumping at about ___ psi

Back 33

85

Front 34

If your truck has a dual air system and one of the systems is low on pressure:

Back 34

Either the front or rear brakes will not be fully operational.

Front 35

The air compressor governor controls:

Back 35

When air is pumped into the air tanks.

Front 36

If your truck or bus has dual parking control valves, you can use pressure from a separate tank to:

Back 36

Release spring emergency/parking brakes to move a short distance.

Front 37

If your truck's air compressor has its own oil supply, when should you first check the oil level?

Back 37

Before driving.

Front 38

The stop light switch:

Back 38

Turns on the brake lights to warn drivers behind you.

Front 39

You are on a steep downgrade and have reached your "safe" speed of 40 mph. You would apply the service brakes until your speed drops to ___ mph.

Back 39

35

Front 40

The braking power of the spring brakes:

Back 40

Depends on the service brakes being in adjustment.