Air Brakes

Front 1

Oil and water usually collect in compressed air tanks..if you do not have a automotic tank drain, when should you drain the air tanks

Back 1

At every working day

Front 2

Why drain water from the compressed air tanks

Back 2

Water freezes during cold weather and causes brake failure

Front 3

The air brake system tryck or bus should not leak at a rate if more than --- psi per minute with the engine off and the brakes relased

Back 3

2

Front 4

To make an emergency stop with air brakes using the stab braking method

Back 4

Press hard on brake pedals, when the wheels lock release. And if the wheels start rolling again brake

Front 5

You should know that your brakes are fading when

Back 5

You have to brake harder on a downgrade

Front 6

If the air comressor should develop a leak what keeps the air in thr tank

Back 6

The one way check valve.

Front 7

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

Back 7

Park on level ground chock the wheels and relase the parking brakes

Front 8

The application pressure gauge shows how much pressure you have

Back 8

When apply to the brakes

Front 9

The spring brakes used on the chambers in a stright truck will bring you to a stop when air pressure drop below--- psi

Back 9

20

Front 10

The safety valeve is set automatically reduce pressure at ---psi

Back 10

150

Front 11

Your truck has a dual air system and one of the system looses its pressure what will happen

Back 11

Either the front or the back brake willnot be fully functional

Front 12

1f your truck or bus has dual parking control valves, you can use pressure from a separate tank to:

Back 12

Release the spring emergency/parking brake show you can move a short distance

Front 13

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 13

45

Front 14

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

Back 14

Air pressure

Front 15

The air compressor stops pumping air at at what psi?

Back 15

125

Front 16

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

Back 16

55

Front 17

Excessive use ofthe service brakes results in overheating which can lead to:

Back 17

Expansion of brake drum

Front 18

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

Back 18

S-cam drum

Front 19

. If you must make an emergency stop, brake so you

Back 19

Can steer and your veicle stays in a straight line

Front 20

The braking power of the spring brakes

Back 20

Depend on the service brakes being in adjustment

Front 21

The braking power of the spring brakes

Back 21

Depend on the service brakes being in adjustment

Front 22

The air brake lag distance at 55 mph on dry pavement adds about __ feet.

Back 22

32 feet

Front 23

Total stopping distance for air brakes is longer than that for hydraulic brakes due to __ _ distance

Back 23

Brake lag

Front 24

It is accepted that too much heat caused by using your brakes too often can also cause

Back 24

Brake fade or failure

Front 25

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

Back 25

The loss of brake air pressure

Front 26

The brake system that applies and releases the b1 .akes when the driver uses the brake pedal is the brake system.

Back 26

Service

Front 27

A slack adjuster's free play needs to be adjusted if it is more than about __ how many inches when you pull hard on it?

Back 27

1 inch

Front 28

An air brake system is fully charged at what psi?

Back 28

125

Front 29

The brake pedal in an air brake system

Back 29

Controls the air pressure applied to put on the brakes

Front 30

The s-cam

Back 30

Forces the brake shoes against the inside of the brake drum

Front 31

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

Back 31

Let the air out of the spring brakes

Front 32

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

Back 32

If you brakes are very hot

Front 33

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

Back 33

Never

Front 34

What is the first thing you should do when a low air pressure warning comes on:

Back 34

Stop and safely park as soon as possible

Front 35

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

Back 35

Spring pressure

Front 36

Air braking takes more time than hydraulic braking because air:

Back 36

Takes more time to flow through the lines than hydraulic fluid

Front 37

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

Back 37

Brake drum

Front 38

If air pressure is NOT build up fast enough within the correct amount of time

Back 38

You air pressure may drop too low during driving.

Front 39

The proper method of braking when going down a 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 39

5

Front 40

In ideal conditions a truck or bus with an air brake going at 55 mph would require stopping distance of how many feet?

Back 40

More than 300 feet

Front 41

It is not safe to drive a vehicle that has brake drums with cracks that are longer than __ of the wid_t_h, ofthe friction area

Back 41

1/2

Front 42

Why must air tanks be drained

Back 42

To drain moisture and oil out of tank

Front 43

It is possible to have an air leak in one system which will not affect the other

Back 43

True

Front 44

Both systems run off of the same air compressor, so if one air compressor malfunctions you will not be able to build or maintain pressure in either system

Back 44

True

Front 45

All '~v.ehicles with air brakes must have a low pressure warning signal.

Back 45

True

Front 46

What are spring brakes

Back 46

If the air brakes leak down springs press the brakes on to stop the vehicle