Ca Cdl Air Brakes

Front 1

The air compressor should STOP pumping at about ___ psi

Back 1

125

Front 2

The application pressure gauge shows how much air pressure you :

Back 2

Are applying to the brakes

Front 3

If your truck has a properly functioning dual air brake system and minimum size air tanks, the air pressure should build from 85 to 100 psi within ___ seconds.

Back 3

45

Front 4

During normal driving, spring brakes are usually held back by:

Back 4

Air pressure

Front 5

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

Back 5

Spring pressure

Front 6

Modern air brake systems are three different systems combined together. They are the service, parking and the ____ brakes.

Back 6

Emergency

Front 7

The air supply pressure gauge shows how much pressure:

Back 7

Is in the air tanks

Front 8

All air brake equipped vehicles have:

Back 8

An air supply pressure gauge

Front 9

The parking or emergency brakes of trucks and buses can be legally held on by ____ pressure.

Back 9

Spring

Front 10

The stop light switch:

Back 10

Turns on the brake lights to warn drivers behind you

Front 11

When you apply the brakes, the brake shoes/linings are pressured against the:

Back 11

Brake drum

Front 12

If your vehicle has an alcohol evaporator, it is there to:

Back 12

Reduce the risk of ice in air brake valves in cold weather

Front 13

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

Back 13

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

Front 14

Why should you drain water from compressed air tanks?

Back 14

Water can freeze in cold weather and cause brake failure.

Front 15

If air pressure does not build up fast enough within the correct amount of time:

Back 15

Your air pressure may drop too low during driving

Front 16

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

Back 16

55

Front 17

The spring brakes used on tractors and straight trucks will bring your truck to a stop when the air pressure drops below ___ psi

Back 17

20

Front 18

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

Back 18

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

Front 19

To check the brake slack on s-cam brakes, you should park on:

Back 19

Level ground, chock the wheels, and release the parking brakes.

Front 20

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 20

2

Front 21

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

Back 21

3 psi in one minute

Front 22

The safety valve is set to automatically reduce pressure at ___ psi

Back 22

150

Front 23

Air braking takes more time than hydraulic braking because air:

Back 23

Takes more time to flow through the lines than hydraulic fluid.

Front 24

Total stopping distance for vehicles with air brakes is longer than that for vehicles with hydraulic brakes due to ___ distance

Back 24

Brake lag

Front 25

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

Back 25

Whenever you leave the vehicle unattended

Front 26

A truck with air brakes going 55 mph would require a stopping distance of:

Back 26

More than 300 ft

Front 27

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

Back 27

32

Front 28

The use of air brakes on a downgrade is only a supplement to the:

Back 28

Braking effect of the engine

Front 29

Excessive heat in the brakes can cause the:

Back 29

Brakes to fade or fail

Front 30

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 30

35

Front 31

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, and then release your speed.

Back 31

5

Front 32

Emergency slab braking is when you:

Back 32

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

Front 33

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

Back 33

If the brakes are very hot (eg after just coming down a steep grade)

Front 34

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

Back 34

Expansion of the brake drums

Front 35

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

Back 35

Let the air out of the air brake system.

Front 36

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

Back 36

Can steer and so your vehicle stay in a straight line

Front 37

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

Back 37

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

Front 38

The air compressor governor controls:

Back 38

When air is pumped into the air tanks

Front 39

The brake pedal in an air brake system:

Back 39

Controls the air pressure applied to put on the brakes.

Front 40

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

Back 40

Service

Front 41

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

Back 41

100

Front 42

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 42

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

Front 43

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

Back 43

either the front or rear brakes will not be fully operational

Front 44

You should know that your brakes are fading when:

Back 44

you have to push harder on the brake pedal to control your speed on a downgrade

Front 45

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

Back 45

Never

Front 46

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

Back 46

100

Front 47

The braking power of the spring brakes:

Back 47

Depends on the service brakes being in adjustment

Front 48

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

Back 48

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

Front 49

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

Back 49

The loss of brake air pressure

Front 50

Emergency controlled braking is when you:

Back 50

Apply the brakes as hard as you can without locking the wheels.

Front 51

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

Back 51

Before driving