暗記メーカー

暗記メーカー

​
ログイン

air brakes

air brakes
85問 • 1年前
  • ユーザ名非公開
    • 通報

    問題一覧

  • 1

    Oil and water usually collect in compressed air tanks. If you do not have an automatic tank drain, when should you drain the air tanks?

    After every working day.

  • 2

    What is the S-cam used for?

    To apply the brakes.

  • 3

    The S-cam:

    Forces the brake shoes against the inside of the brake drum.

  • 4

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

    Service brake system.

  • 5

    Why drain water from the compressed air tanks?

    Water can freeze in cold weather and cause brake failure.

  • 6

    To Make an emergency stop with air brakes, using the stab braking method, you should:

    Press on the brake pedal as hard as you can, release the brakes when the wheels locked, put on the brakes again when the wheels start rolling.

  • 7

    You should know that your brakes are fading when:

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

  • 8

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

    32 Feet

  • 9

    If the air compressor should develop a leak, what keeps the air in the tanks?

    The one way check valve

  • 10

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

    Park on level ground, chock the wheels, and release the parking brakes.

  • 11

    The application pressure gauge shows how much pressure you have:

    when you are applying to the brakes

  • 12

    The spring brakes used on the chambers in a straight truck will bring you to a stop when air pressure drops below_ psi.

    20

  • 13

    The safety valve is set to automatically reduce pressure at __ psi.

    150

  • 14

    Your truck has a dual air system and one of the system loses its pressure. What Will Happen ?

    Either the front or back brake will not be fully operational

  • 15

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

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

  • 16

    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?

    45

  • 17

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

    Air Pressure

  • 18

    The air compressor stops pumping air at at what psi?

    125

  • 19

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

    55

  • 20

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

    Expansion of the brake drums

  • 21

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

    s-cam drum.

  • 22

    If you must make an emergency stop, brake so you

    Can steer and your vehicle stays in a straight line.

  • 23

    The braking power of the spring brakes

    Depends on the service brakes being in adjustment.

  • 24

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

    32 Feet.

  • 25

    Total stopping distance for air brakes is longer than that for hydraulic brakes due to ____ distance.

    Brake lag

  • 26

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

    Brake fade or failure

  • 27

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

    The loss of brake air pressure

  • 28

    The brake system that applies and releases the Brakes when the driver uses the brake pedal is the _______ brake system.

    Service

  • 29

    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?

    1 Inch

  • 30

    An air brake system is fully charged at what psi?

    125

  • 31

    The brake pedal in an air brake system:

    Controls the air pressure applied to put on the brakes

  • 32

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

    Let the air out of the spring brakes.

  • 33

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

    If your brakes are very hot.

  • 34

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

    Never.

  • 35

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

    Stop and safely park as soon as possible.

  • 36

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

    Spring pressure

  • 37

    Air Braking takes more time than hydraulic braking because air:

    Takes more time to flow through the lines than hydraulic fluid

  • 38

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

    Brake drum

  • 39

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

    Your air pressure may drop too low during driving

  • 40

    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.

    5

  • 41

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

    More than 300 feet

  • 42

    It is not safe to drive a vehicle that has brake drums with cracks that are longer than _____ of the width of the friction area.

    1/2

  • 43

    Why must air tanks be drained?

    To drain moisture and oil out of tank

  • 44

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

    True

  • 45

    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

    True

  • 46

    All vehicles with air brakes must have a low pressure warning signal

    True

  • 47

    What are spring brakes?

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

  • 48

    Front wheel brakes are good under all conditions

    True

  • 49

    When you apply your brakes, the air brake system works with an electric switch, by air pressure, to turn on the brake lights

    true

  • 50

    What do air brakes use to make the brakes work?

    Compressed air

  • 51

    The service brake applies and releases:

    The brake when you use the brake pedal during normal driving.

  • 52

    The parking brake applies and releases:

    The parking brakes when you use the parking brake control

  • 53

    The emergency brake system:

    Uses parts of the service and parking brake system to stop the vehicle in the event of a brake system failure.

  • 54

    The governor controls when the air compressor will pump into the air storage tanks

    True

  • 55

    When you put the brakes on by pushing down on the brake pedal:

    Air pressure is applied to the brake pads

  • 56

    What is a dual air brake system?

    A 'two brake system, one operates the front brakes and one operates the back brakes

  • 57

    What are the slack adjusters?

    It is an adjusting nut on the the backside of the brake drum used for adjusting the brakes.

  • 58

    How can you check the slack adjuster?

    Park on level ground, turn off parking brakes, pull hard on each slack adjuster. It shouldn't move more than one inch

  • 59

    How can you test the low pressure warning signal?

    Shut off the engine with enough air pressure, turn on the electrical power and step on and off the brake pedal until the low air pressure warning signal comes on.

  • 60

    Air brake equipped vehicles must have:

    A supply pressure gauge

  • 61

    The modulating control valve is?

    A spring-loaded valve that will let you put on the brakes on slowly if the service brakes fail

  • 62

    What are the maximum leakage rates?

    Less than 2 psi in one minute for single vehicles and less than 3 psi in one minute for combination vehicles

  • 63

    What factors can cause brakes to fade or fail?

    overheating, low air pressure, and not relying on the engine braking effect

  • 64

    Why should you be in the proper gear before starting down a hill?

    So you only have to apply the brake just hard enough to feel a definite slowdown

  • 65

    If oil and water collects in the air tanks what can happen to the brakes?

    The brakes could fail

  • 66

    What is the purpose of an alcohol evaporator?

    To reduce the risk of ice in the brake valves and other parts in cold weather.

  • 67

    What is another name for controlled braking?

    Squeeze breaking.

  • 68

    The brake chamber fills with air pushing the rod out which moves the ______ _ which twists the ______ _

    Slack adjuster and brake camshaft.

  • 69

    To test the air service brakes you should:

    Break firmly while moving forward.

  • 70

    The driver must be able to see a low pressure warning which comes on before pressure in the service aif tank falls below.

    60 psi

  • 71

    Converter dollies built on or after March 1, 1998 are required to have anti lock brakes. These dollies will have

    A yellow malfunction lamp on the left side of the dolly.

  • 72

    Wh'tdl of these is the most important thing to remember about emergency braking?

    If the wheels are skidding, you cannot control the vehicle.

  • 73

    To correct a drive-wheel braking skid, you should:

    Stop braking, turn quickly and counter steer.

  • 74

    How do you test the hydraulic brakes for leaks?

    Pump the brake pedal three times then apply firm pressure to the pedal and hold for five seconds. The pedal should not move.

  • 75

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

    Emergency.

  • 76

    The air supply pressure gauge shows how much pressure:

    Is in the air tanks.

  • 77

    The parking or emergency brakes of trucks or buses can legally be held on by______pressure

    Spring.

  • 78

    Air brake equipped vehicles have:

    An air supply pressure gauge.

  • 79

    The stop light switch:

    Turns on the brake lights to warn drivers behind you.

  • 80

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

    3 psi in one minute

  • 81

    Was air brake vehicles the parking brake should be used.

    Whenever you leave the vehicle unattended.

  • 82

    The air compressor governor Controls

    When air is pumped into the air storage tanks

  • 83

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

    100

  • 84

    The modulating control valve allows you to control the:

    Spring Breaks

  • 85

    You are on a steep down grade and have reached your safe speed of 40 mph. You would apply the service brakes until your speed drops to_ mph

    35

    • CDL GENERAL QUESTIONS

    CDL GENERAL QUESTIONS

    ユーザ名非公開 · 81問 · 1年前

    CDL GENERAL QUESTIONS

    CDL GENERAL QUESTIONS

    81問 • 1年前
    ユーザ名非公開

    問題一覧

  • 1

    Oil and water usually collect in compressed air tanks. If you do not have an automatic tank drain, when should you drain the air tanks?

    After every working day.

  • 2

    What is the S-cam used for?

    To apply the brakes.

  • 3

    The S-cam:

    Forces the brake shoes against the inside of the brake drum.

  • 4

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

    Service brake system.

  • 5

    Why drain water from the compressed air tanks?

    Water can freeze in cold weather and cause brake failure.

  • 6

    To Make an emergency stop with air brakes, using the stab braking method, you should:

    Press on the brake pedal as hard as you can, release the brakes when the wheels locked, put on the brakes again when the wheels start rolling.

  • 7

    You should know that your brakes are fading when:

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

  • 8

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

    32 Feet

  • 9

    If the air compressor should develop a leak, what keeps the air in the tanks?

    The one way check valve

  • 10

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

    Park on level ground, chock the wheels, and release the parking brakes.

  • 11

    The application pressure gauge shows how much pressure you have:

    when you are applying to the brakes

  • 12

    The spring brakes used on the chambers in a straight truck will bring you to a stop when air pressure drops below_ psi.

    20

  • 13

    The safety valve is set to automatically reduce pressure at __ psi.

    150

  • 14

    Your truck has a dual air system and one of the system loses its pressure. What Will Happen ?

    Either the front or back brake will not be fully operational

  • 15

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

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

  • 16

    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?

    45

  • 17

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

    Air Pressure

  • 18

    The air compressor stops pumping air at at what psi?

    125

  • 19

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

    55

  • 20

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

    Expansion of the brake drums

  • 21

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

    s-cam drum.

  • 22

    If you must make an emergency stop, brake so you

    Can steer and your vehicle stays in a straight line.

  • 23

    The braking power of the spring brakes

    Depends on the service brakes being in adjustment.

  • 24

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

    32 Feet.

  • 25

    Total stopping distance for air brakes is longer than that for hydraulic brakes due to ____ distance.

    Brake lag

  • 26

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

    Brake fade or failure

  • 27

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

    The loss of brake air pressure

  • 28

    The brake system that applies and releases the Brakes when the driver uses the brake pedal is the _______ brake system.

    Service

  • 29

    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?

    1 Inch

  • 30

    An air brake system is fully charged at what psi?

    125

  • 31

    The brake pedal in an air brake system:

    Controls the air pressure applied to put on the brakes

  • 32

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

    Let the air out of the spring brakes.

  • 33

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

    If your brakes are very hot.

  • 34

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

    Never.

  • 35

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

    Stop and safely park as soon as possible.

  • 36

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

    Spring pressure

  • 37

    Air Braking takes more time than hydraulic braking because air:

    Takes more time to flow through the lines than hydraulic fluid

  • 38

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

    Brake drum

  • 39

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

    Your air pressure may drop too low during driving

  • 40

    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.

    5

  • 41

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

    More than 300 feet

  • 42

    It is not safe to drive a vehicle that has brake drums with cracks that are longer than _____ of the width of the friction area.

    1/2

  • 43

    Why must air tanks be drained?

    To drain moisture and oil out of tank

  • 44

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

    True

  • 45

    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

    True

  • 46

    All vehicles with air brakes must have a low pressure warning signal

    True

  • 47

    What are spring brakes?

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

  • 48

    Front wheel brakes are good under all conditions

    True

  • 49

    When you apply your brakes, the air brake system works with an electric switch, by air pressure, to turn on the brake lights

    true

  • 50

    What do air brakes use to make the brakes work?

    Compressed air

  • 51

    The service brake applies and releases:

    The brake when you use the brake pedal during normal driving.

  • 52

    The parking brake applies and releases:

    The parking brakes when you use the parking brake control

  • 53

    The emergency brake system:

    Uses parts of the service and parking brake system to stop the vehicle in the event of a brake system failure.

  • 54

    The governor controls when the air compressor will pump into the air storage tanks

    True

  • 55

    When you put the brakes on by pushing down on the brake pedal:

    Air pressure is applied to the brake pads

  • 56

    What is a dual air brake system?

    A 'two brake system, one operates the front brakes and one operates the back brakes

  • 57

    What are the slack adjusters?

    It is an adjusting nut on the the backside of the brake drum used for adjusting the brakes.

  • 58

    How can you check the slack adjuster?

    Park on level ground, turn off parking brakes, pull hard on each slack adjuster. It shouldn't move more than one inch

  • 59

    How can you test the low pressure warning signal?

    Shut off the engine with enough air pressure, turn on the electrical power and step on and off the brake pedal until the low air pressure warning signal comes on.

  • 60

    Air brake equipped vehicles must have:

    A supply pressure gauge

  • 61

    The modulating control valve is?

    A spring-loaded valve that will let you put on the brakes on slowly if the service brakes fail

  • 62

    What are the maximum leakage rates?

    Less than 2 psi in one minute for single vehicles and less than 3 psi in one minute for combination vehicles

  • 63

    What factors can cause brakes to fade or fail?

    overheating, low air pressure, and not relying on the engine braking effect

  • 64

    Why should you be in the proper gear before starting down a hill?

    So you only have to apply the brake just hard enough to feel a definite slowdown

  • 65

    If oil and water collects in the air tanks what can happen to the brakes?

    The brakes could fail

  • 66

    What is the purpose of an alcohol evaporator?

    To reduce the risk of ice in the brake valves and other parts in cold weather.

  • 67

    What is another name for controlled braking?

    Squeeze breaking.

  • 68

    The brake chamber fills with air pushing the rod out which moves the ______ _ which twists the ______ _

    Slack adjuster and brake camshaft.

  • 69

    To test the air service brakes you should:

    Break firmly while moving forward.

  • 70

    The driver must be able to see a low pressure warning which comes on before pressure in the service aif tank falls below.

    60 psi

  • 71

    Converter dollies built on or after March 1, 1998 are required to have anti lock brakes. These dollies will have

    A yellow malfunction lamp on the left side of the dolly.

  • 72

    Wh'tdl of these is the most important thing to remember about emergency braking?

    If the wheels are skidding, you cannot control the vehicle.

  • 73

    To correct a drive-wheel braking skid, you should:

    Stop braking, turn quickly and counter steer.

  • 74

    How do you test the hydraulic brakes for leaks?

    Pump the brake pedal three times then apply firm pressure to the pedal and hold for five seconds. The pedal should not move.

  • 75

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

    Emergency.

  • 76

    The air supply pressure gauge shows how much pressure:

    Is in the air tanks.

  • 77

    The parking or emergency brakes of trucks or buses can legally be held on by______pressure

    Spring.

  • 78

    Air brake equipped vehicles have:

    An air supply pressure gauge.

  • 79

    The stop light switch:

    Turns on the brake lights to warn drivers behind you.

  • 80

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

    3 psi in one minute

  • 81

    Was air brake vehicles the parking brake should be used.

    Whenever you leave the vehicle unattended.

  • 82

    The air compressor governor Controls

    When air is pumped into the air storage tanks

  • 83

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

    100

  • 84

    The modulating control valve allows you to control the:

    Spring Breaks

  • 85

    You are on a steep down grade and have reached your safe speed of 40 mph. You would apply the service brakes until your speed drops to_ mph

    35