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

A.  Fluid pressure

B.  Spring pressure

C.  Air pressure

D.  Any of the above

B.  Spring pressure

2.  A straight truck or bus air brake system should not leak at a rate of more than ____ psi per minute with the engine off and the brakes released

A.  1

B.  2

C.  3

D.  4

B.  2

3.  Your vehicle has a dual air brake system.  If a low air pressure warning comes on for the secondary system, you should?

A.  Bring the vehicle to a safe stop and continue only when the system is fixed

B.  Reduce your speed and test the remaining system while under4 way

C.  Reduce your speed and drive to the nearest garage for repairs

D.  Continue at a normal speed if only the secondary system fails

A.  Bring the vehicle to a safe stop and continue only when the system is fixed

4.  If your vehicle has an alcohol evaporator it is there to?

A.  Rid the wet tank of alcohol that condenses and sits at the bottom

B.  Eliminate the need for daily tank draining

C.  Boost engines

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

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

5.  Air braking takes more time than hydraulic braking because air

A.  Brakes use different brake drums

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

C.  Brakes require heavier return springs

D.  Is always leaking through airline fittings

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

6.  The brake pedal in an air brake system

A.  Controls the speed of the air compressor

B.  Always needs to be held down halfway during normal driving

C.  Controls the air pressure applied to put on the brakes

D.  Is connected to slack adjusters by a series of rods and linkages

C.  Controls the air pressure applied to put on the brakes

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

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

B.  Apply more brake pressure if the main tank is getting low

C.  Stay parked twice as long with your service air pressure

D.  Balance the service brake system whenever you are parked

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

8.  Modern air brake systems combine three different systems. They are the service, parking and the

A.  Emergency

B.  Foot

C.  S-cam

D.  Drum

A.  Emergency

9.  To check the free play of manual slack adjusters on S-cam brakes, you should park on

A.  Level ground with the parking brake then apply the service brake

B.  Level ground, Chock the wheels and turn off the parking brakes

C.  Level ground and drain off air pressure before adjusting

D.  A slight grade, release the parking brakes, apply the service brakes and check for vehicle movement

B.  Level ground, Chock the wheels and turn off the parking brakes

10.  Of the choices below, the first thing to do when a low air pressure warning comes on is

A.  Stop and safely park as soon as possible

B.  Shift to the next higher gear

C.  Adjust the brake pedal for more travel

D.  Open the air supply control valve

A.  Stop and safely park as soon as possible

11.  The air compressor governor controls

A.  The speed of the air compressor

B.  When the brake chambers release pressure

C.  Air pressure applied to the brakes

D.  When air is pumped into the air tanks

D.  When air is pumped into the air tanks

12.  The braking power of the spring brakes

A.  Is not affected by the condition of the service brakes

B.  Can only be tested by highly trained brake service people

C.  Depends on the service brakes being in adjustment

D.  Increases when the service brakes are hot

C.  Depends on the service brakes being in adjustment

13.  All air brake equipped vehicles have

A.  At least one brake heater

B.  A hydraulic system in case the air system fails

C.  A supply pressure gauge

D.  An air use gauge

C.  A supply pressure gauge

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

A.  Can steer hard while braking hard

B.  Use the full power of the brakes and lock them

C.  Can steer and your vehicle stays in a straight line

D.  Use the hand brake first

C.  Can steer and your vehicle stays in a straight line

15.  The application pressure gauge shows how much air pressure you

A.  Have used in this trip

B.  Have in the air tanks

C.  Are applying to the brakes

D.  None of the above

C.  Are applying to the brakes

16.  If you do not have automatic tank drains how often should you drain the oil and water from the bottom of compressed air storage air tanks?

A.  After every four hours of service

B.  At the end of each day of driving

C.  Once a week

D.  Every other week

B.  At the end of each day of driving

17.  You should know that your brakes are fading when

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

B.  The brake pedal feels spongy when pressure is applied

C.  Pressure on the brake pedal is released and speed increases

D.  Less pressure is needed on the brake pedal for each stop

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

18.  If your vehicle has an alcohol evaporator every day during cold weather you should

A.  Change the alcohol from a new bottle

B.  Clean the air filter with alcohol

C.  Check the oil  for alcohol content

D.  Check and fill the alcohol level

D.  Check and fill the alcohol level

19.  Why drain water from compressed air tanks?

A.  The low boiling point of water reduces braking power

B.  Water can freeze in cold weather and cause brake failure

C.  Water cools the compressor too much

D.  To keep from fouling the air compressor oil

B.  Water can freeze in cold weather and cause brake failure

20.  To test air service brakes you should brake firmly when moving slowly forward. The brakes are ok if you notice

A.  The vehicle "pull" to one side

B.  An unusual feel

C.  A delayed stopping action

D.  None of the above

D.  None of the above

21.  For long downhill grades experts recommend light, steady pedal pressure instead of on-again, off-again braking. Why?

A.  Air usage is less with light steady pressure

B.  Brake lining do not heat up as much with light pressure

C.  It works better with a low gear in controlling speed.

D.  All of the above

D.  All of the above

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

A.  40

B.  50

C.  60

D.  80

C.  60

23.  During normal driving spring brakes are usually held back by

A.  Bolts

B.  Air pressure

C.  Spring pressure

D.  Centrifugal force

B.  Air pressure

24.  In air brake vehicles the parking brakes should be used

A.  As little as possible

B.  Any time the vehicle is parked

C.  To hold your speed when going downhill

D.  Only during pre- and post-trip inspections

B.  Any time the vehicle is parked

25.  Emergency stab braking is when you

A.  Press hard on the brake pedal and apply full hand valve until you stop.

B.  Apply the hand valve for one second then push hard on the pedal

C.  Use light steady pressure on the brake pedal

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

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

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

A.  1 psi in 60 seconds

B.  1 psi in one minute

C.  2 psi in 45 seconds

D.  3 psi in on minute

D.  3 psi in on minute

27.  Which of the following statements about brakes is true?

A.  The heavier a vehicle or the faster it is moving the more heat the brakes have to absorb to stop it

B.  Brakes have more stopping power when they get very hot

C.  Brake drums cool very quickly

D.  All of the above

A.  The heavier a vehicle or the faster it is moving the more heat the brakes have to absorb to stop it

28.  The purpose of engine retarders is to

A.  Provide emergency brakes

B.  Help slow the vehicle while driving and reduce brake wear

C.  Apply extra braking power to the non-drive axles

D.  Help prevent skids an slides

B.  Help slow the vehicle while driving and reduce brake wear

29.  If your vehicle has an alcohol evaporator it is there to

A.  Get rid of alcohol that condenses in the air tanks

B.  Let the driver skip the daily tank draining

C.  Increase tank pressure the way superchargers boost engines

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

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

30. The air supply pressure gauge shows the driver how much pressure:

A. Has been used in this trip

B. Is available in the air tanks

C. Is being sent to the brake chambers

D. None of the above

B. Is available in the air tanks

31. Which brake system applies and releases the brakes when the driver uses the brake pedal?

A. the emergency brake system

B. the service brake system

C. the parking brake system

D. none of the above

B. the service brake system

32. When using the parking brakes or emergency brakes, what type of pressure is being used?

A. Fluid pressure

B. Spring pressure

C. Air pressure

D. any of the above

B. Spring pressure

33. Three different systems are found on modern air brake systems: Service brakes, the Parking brake and the:

A. Emergency brake

B. Foot brakes

C. S-cam brakes

D. Drum brakes

A. Emergency brake

34. Air loss in a single vehicle (not a combination unit) should not be more than ________ with the engine off & the brakes on.

A. 1 psi in 30 seconds

B. 1 psi in 1 minute

C. 2 psi in 45 seconds

D. 3 psi in 1 minute

D. 3 psi in 1 minute

35. The vehicle must have a warning device which comes on when air pressure in the service air tanks falls below:

A. 40 psi

B. 50 psi

C. 60 psi

D. 80 psi

C. 60 psi

36. Air brake equipped vehicles must have:

A. at least 3 air tanks

B. a hydraulic braking system, in case the air system fails

C. an air pressure gauge to show the pressure available for braking

D. an air application gauge to show air used by the brake chambers for braking

C. an air pressure gauge to show the pressure available for braking

37. How do you check the free play in manual slack adjusters?

A. Stop on level ground & apply the emergency brakes

B. Park on level ground, chock wheels, release the parking brakes & pull slack adjusters

C. Park on level ground & drain off air pressure before making adjustments

D. Apply the service brakes by hand at the brake chambers & watch the slack adjuster move

B. Park on level ground, chock wheels, release the parking brakes & pull slack adjusters

38. The most common type of foundation brake found on heavy commercial vehicles is:

A. Disc

B. Wedge & Drum

C. S-cam drum

D. None of the above

C. S-cam drum

39. The air compressor governor controls:

A. the rpm's of the air compressor

B. whether the compressor is in good mechanical condition

C. air pressure applied to the brakes

D. when the compressor will pump air into the storage tanks

D. when the compressor will pump air into the storage tanks

40. The brake pedal:

A. is the main lever in the system

B. can be a foot rest during normal driving

C. controls the air pressure applies to operate the brakes

D. exerts force on the slack adjusters by rods & connectors

C. controls the air pressure applies to operate the brakes

41. What will determine how effective the spring emergency brakes or the parking brakes work?

A. Has nothing to do with the condition of the service brakes

B. Can only be tested by highly trained brake service people

C. Depends on the adjustment of the service brakes

D. The braking power increased when the service brakes are hot

C. Depends on the adjustment of the service brakes

42. When a failure occurs in the service brake system, the system you need to stop the vehicle is the:

A. Parking brake system

B. Emergency brake system

C. Drum brake system

D. The hand brake system

B. Emergency brake system

43. If you vehicle is equipped with an alcohol evaporator, every day during winter weather you should:

A. Check & fill the alcohol level

B. Change the alcohol from a new bottle

C. Oil the system with 5 weight oil

D. Drain out the alcohol which has accumulated

A. Check & fill the alcohol level

44. What turns on the electrical stop light switch in an air brake system?

A. Spring pressure

B. Hydraulic pressure

C. Air pressure

D. The driver, by hand

C. Air pressure

45. Which of the following is okay to find in the air brake system?

A. Oil

B. Air

C. Water

D. All of the above

B. Air

46. If the air system should develop a leak, what will keep the air in the tanks?

A. The governor

B. The tractor protection valve

C. The emergency relay valve

D. The one-way check valve

D. The one-way check valve

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

A. Release the emergency brakes to move a short distance

B. Apply more brake pressure for stopping if the main tank is getting low

C. Stay parked without using up service air pressure

D. Balance the service brake system while you drive

A. Release the emergency brakes to move a short distance

48. In air equipped vehicles, you use the parking brakes when?

A. Slowing down

B. As little as possible

C. Whenever you park the vehicle

D. Only during pre- and post-trip inspections

C. Whenever you park the vehicle

49. During normal operations, the parking & emergency brakes are usually held back by:

A. Air pressure

B. Spring Pressure

C. Centrifugal force

D. Bolts or clamps

A. Air pressure

50. A combination vehicle air brake system cannot leak more than ____ psi per minute with the engine off & the brakes released.

A. 1

B. 2

C. 3

D. 4

C. 3

51. A straight truck or bus air brake system cannot leak more than ____ psi per minute with the engine off & the brakes released.

A. 1

B. 2

C. 3

D. 4

B. 2

52. You must make a quick emergency stop. You should brake so you:

A. Can steer hard while braking hard

B. Use the full power of the brakes & lock them

C. Can stay in a straight line & maintain steering control

D. Burn up the hand brake first

C. Can stay in a straight line & maintain steering control

53. Why should you not fan the brakes on & off during long downgrades?

A. Air usage is less when fanning

B. Brake linings do not get hot when fanning

C. The short time off the brakes foes not allow brake cooling

D. None of the above

C. The short time off the brakes foes not allow brake cooling

54. Which of the following answers is most correct about using on a long and/or steep downgrade?

A. Use the braking effects of the engine & when vehicle speed reaches "safe" speed, apply brakes firmly until vehicle speed is reduces to approx. 5 mph below "safe" speed.

B. Use stab braking

C. Use only trailer brakes to maintain "safe" speed

D. Apply brakes when vehicle speed reaches 5 mph over "safe" speed & then release when speed of vehicle is back at "safe" speed

A. Use the braking effects of the engine & when vehicle speed reaches "safe" speed, apply brakes firmly until vehicle speed is reduces to approx. 5 mph below "safe" speed.

55. To use the stab braking technique during emergency, you:

A. Pump the brake pedal rapidly & lightly

B. Brake hard with the pedal until the wheels lock, then get off them until the wheels begin rolling again

C. Brake hard with the pedal until the wheels lock, then get off the brakes for as long as the wheels were locked

D. Brake hard with pedal and hand valve until you stop

B. Brake hard with the pedal until the wheels lock, then get off them until the wheels begin rolling again

56. The safety valve in the air compressor tank is set to open at:

A. 150 psi

B. 200 psi

C. 100 psi

D. 175 psi

A. 150 psi

57. The air compressor governor controls:

A. When the brakes should be applied

B. When the air compressor pumps air into the storage tanks

C. When the warning light is activated

D. When the air is released from the tank

B. When the air compressor pumps air into the storage tanks

58. The governor stops pumping air when it reaches the "cut out" level, or around:

A. 125 psi

B. 200 psi

C. 225 psi

D. 175 psi

A. 125 psi

59. The governor allows air to start pumping air when it reaches the "cut in" level, or around:

A. 200 psi

B. 100 psi

C. 150 psi

D. 125 psi

B. 100 psi

60. You should use the parking brake:

A. Only on steep hills

B. On level surfaces

C. Any time you park

D. When the brakes are hot

C. Any time you park

61. An air tank is equipped with a drain valve to remove:

A. Air & water

B. Oil & air

C. Water & oil

D. Dirt & oil 

C. Water & oil

62. The air compressor (newer model vehicles) is connected to the engine through:

A. Gears

B. Hoses

C. V Belt

D. both A & B

D. both A & B

63. Some air brake systems have an alcohol evaporator which helps:

A. Reduce the risk of ice in the air brake vales during cold weather

B. Remove oil from the air lines

C. Reduce the risk of water in the air brake valves in warm weather

D. Remove fuel from the air lines

A. Reduce the risk of ice in the air brake vales during cold weather

64. The air tank should be drained how often?

A. Once a week

B. Once a day

C. Every 4 hours

D. Every 2 or 3 days

B. Once a day

65. When the safety valve releases air it means that:

A. The pressure has exceeded 150 psi

B. Too much air is in the air compressor

C. Something is wrong, you should have it checked by a mechanic

D. All of the above

D. All of the above

66. Brake drums:

A. Are bolted to the wheels

B. Are located at each of the vehicle's axles

C. Hold the brake shoes and linings

D. All of the above

D. All of the above

67. Which type of brake is the most common in commercial vehicles?

A. Wedge brakes

B. Disk brakes

C. S-cam brakes

D. Drum brakes

C. S-cam brakes

68. An air pressure gauge:

A. Shoes how much pressure you are applying to the brakes

B. Is connected to the generator

C. Releases air when you accelerate

D. Prevents brake failure

A. Shoes how much pressure you are applying to the brakes

69. When you apply pressure to the brake pedal, you are:

A. Pushing against a spring and against air pressure to the brakes

B. Releasing air pressure to the brakes

C. Reducing air in the tanks

D. Activating the safety valve

A. Pushing against a spring and against air pressure to the brakes

70. All vehicles with air brakes are required to have a low pressure warning signal.  This could be:

A. A red light

B. A wig wag mechanical arm (older models)

C. A buzzer

D. Any one of the above

D. Any one of the above

71. When the low pressure warning is activated, you should:

A. Wait for the air brakes to come on automatically

B. Bring the vehicle to a safe stop while you still control the brakes

C. Monitor your air pressure gauage & maintain highway speeds

D. Pump the brake pedal hard to stop 

B. Bring the vehicle to a safe stop while you still control the brakes

72. An emergency brake;

A. Is required on commercial vehicles

B. Must be held on by mechanical force

C. Could be activated by the loss of air pressure

D. All of the above

D. All of the above

73. To check the air compressor governor "cut in" and "cut out" pressures:

A. Run the engine at a fast idle

B. Step on & off the brake to reduce tank pressure

C. Monitor the air pressure gauge

D. All of the above

D. All of the above

74. To check the slack adjusters on S-cam brakes, you should:

A. Leave the parking brakes on and pull on the slack adjuster

B. Wear gloves and pull hard on each slack adjuster

C. Make sure the slack adjusters move more than 1" each way

D. Drain the air from the system and pull on the slack adjusters

B. Wear gloves and pull hard on each slack adjuster

75. With dual air systems, the air pressure should build:

A. from 85 to 100 psi in 45 seconds

B. from 70 to 100 psi in 60 seconds

C. from 85 to 150 psi in 45 seconds

D. from 70 to 150 psi in 60 seconds

A. from 85 to 100 psi in 45 seconds

76. Compressed air is stored:

A. in the hoses

B. in the engine compartment

C. in the fuel tank

D. in the storage tank

D. in the storage tank

77. A fully charged air system typically has ____psi.

A. 100

B. 125

C. 150

D. 175

B. 125

78. To test air leakage rate you should:

A. Leave the engine running & release the service brake

B. Turn off the engine & release the service brake

C. Charge the air system & leave the engine running

D. Depress the brake pedal & monitor the air gauge

B. Turn off the engine & release the service brake

79. A combination vehicle air brake system should not lose air faster than:

A. 2 psi per minute

B. 3 psi per 30 seconds

C. 3 psi per minute

D. 4 psi per minute

C. 3 psi per minute

80. To test your service brakes you should:

A. Stop the vehicle & put he parking brake on

B. Release the parking brake, move forward slowly & depress brakes

C. Put parking brake on & release air pressure

D. Depress brakes when traveling at highway speeds

B. Release the parking brake, move forward slowly & depress brakes

81. Stab braking occurs when you:

A. Press on the brake pedal as hard as you can

B. Release the brakes when the wheels lock up

C. Apply the brakes when the wheels start rolling

D. All of the above

D. All of the above

82. A duel air system:

A. Has 2 air brake systems and 1 set of controls

B. Takes less time to builds air pressure

C. Has 1 set of air tanks and hoses

D. Must have 2 warning alarms

A. Has 2 air brake systems and 1 set of controls

83. Air brakes take longer to stop than hydraulic brakes because:

A. The reaction time is longer for the driver

B. It takes longer for the air to flow through the lines

C. The linings get hotter more quickly

D. None of the above

A. The reaction time is longer for the driver

84. The proper way to go down long grades is to:

A. Use a lower gear and push hard on the brakes

B. Let up on the brakes from time to time to cool them

C. Use a gear & apply light pressure on the brakes

D. Brake on and off down the hill

C. Use a gear & apply light pressure on the brakes

85. To test low pressure warning signal, you should do all BUT the following:

A. Shut the engine off

B. Turn the electrical power on

C. Ask a friend to listen for the signal

D. Step on & off the brake pedal to reduce air pressure

C. Ask a friend to listen for the signal

86. Modern airbrake systems are combined of 3 different systems. They are the service brakes, the parking brakes and the_______________________?

A. S-can brakes

B. Drum brakes

C. Foot brakes

D. Emergency brakes

D. Emergency brakes

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

A. Once a week

B. Every 4 hours

C. Once a day

D. Every other week

C. Once a day

88. Why drain water from the compressed air tanks?

A. A supply pressure gauge

B. Water can freeze in cold weather & cause brake failure

C. The low boiling point of water reduces the braking power

D. Water is needed to cool the compressor

B. Water can freeze in cold weather & cause brake failure

89. Air brake equipped vehicles must have:

A. A supply pressure gauge

B. An application gauge

C. At least 2 brake heaters

D. A back up hydraulic system

A. A supply pressure gauge

90. What can legally hold a parking brake or emergency brake in position for a truck, track tractor or bus?

A. Fluid pressure

B. Air pressure

C. Spring pressure

D. Any of the above

C. Spring pressure

91. Air loss in a straight truck or bus should not be more than ____ psi with the engine off & the brakes on. 

A. 1 psi in 30 seconds

B. 1 psi in 1 minute

C. 2 psi in 45 seconds

D. 3 psi in 1 minute

D. 3 psi in 1 minute

92. To make an emergency stop with air brakes, using stab braking method, you should:

A. Pump the brake pedal rapidly

B. Brake hard until the wheels lock, then get off of the brakes for as much time as the wheels were locked

C. Brake as hard as you can, get off the brakes when wheels lock, reapply the brakes when the wheels begin to roll again

D. Press hard on the brake pedal & apply full hand valve until you stop

C. Brake as hard as you can, get off the brakes when wheels lock, reapply the brakes when the wheels begin to roll again

93. You will know that your brakes are fading when:

A. Pressure on the brake pedal is release & speed increases

B. You have to press harder on the pedal to keep the same speed on a downgrade

C. The brake pedal feels spongy when pressure is applied

D. Less pressure is needed for each stop

B. You have to press harder on the pedal to keep the same speed on a downgrade

94. To check the free-play in the slack adjuster on s-cam brakes you should:

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

B. Stop on level ground & apply the parking brakes

C. Park on level ground & drain the air pressure before checking the slack adjusters

D. Park on a slight grade, release the parking brakes, apply the service brakes & check for movement

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

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

A. The tractor protective valve

B. The emergency relay valve

C. The one way check valve

D. The air compressor

C. The one way check valve

96. When driving down a long steep hill you should:

A. Use stab braking

B. Begin braking when you are 10 mph above your safe speed

C. Release the brakes when you are 5 mph below your safe speed

D. Use the trailer brakes

C. Release the brakes when you are 5 mph below your safe speed

97. The brake system that applies & releases the brakes when the driver uses the brake pedal is the______.

A. Service brake

B. Emergency brake

C. Parking brake

D. None of the above

A. Service brake

98. The most common type of foundation brakes found on heavy vehicles is the______.

A. Disc brake

B. Wedge brake

C. S-can brake

D. None of the above

C. S-can brake

99. Vehicles with air brakes must have:

A. At least 2 air tanks

B. An air pressure gauge to show you how much air pressure is available

C. An air pressure gauge to show you how much pressure is being used

D. None of the above

B. An air pressure gauge to show you how much air pressure is available

100. The driver must be able to see a warning that is given before the air pressure falls below:

A. 80 psi

B. 100 psi

C. 60 psi

D. 20 psi

C. 60 psi

101. Which of the following makes the total stopping distance for air brakes longer than hydraulic brakes?

A. Brake lag distance

B. Action distance

C. Effective braking distance

D. Perception distance

A. Brake lag distance

102. Of the choices below, what is the first thing to do when the low air pressure warning light & buzzer activate?

A. Open the supply control valve

B. Up shift

C. Find a safe place to stop while you still have control of the brakes

D. Adjust the brake pedal

C. Find a safe place to stop while you still have control of the brakes

103. The braking power of the spring brakes:

A. Can only be tested by highly trained brake specialist

B. Depends on the adjustment of the service brakes

C. Increases when the service brakes are hot

D. If not affected by the condition of the service brakes

B. Depends on the adjustment of the service brakes

104. The air compressor governor controls:

A. When the air compressor will pump air into the tanks

B. When air pressure is applied to the service brakes

C. The speed of the air compressor

D. When the brake chambers release air pressure

A. When the air compressor will pump air into the tanks

105. The application pressure gauge shows the driver how much pressure:

A. Has been used on the trip

B. Is available in the tanks

C. Is being applied

D. None of the above

C. Is being applied

106. If your vehicle has an alcohol evaporator, everyday during cold weather you should:

A. Clean the air filter with alcohol

B. Check & fill the alcohol level

C. Change the alcohol bottle

D. Check the oil for alcohol

B. Check & fill the alcohol level

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

A. Spring pressure

B. Bolts or clamps

C. Centrifugal force

D. Air pressure

D. Air pressure

108. Air braking takes more time than hydraulic because air brakes:

A. Need to have air flow through the lines to work properly

B. Use different brake drums

C. Require heavier return

D. All of the above

A. Need to have air flow through the lines to work properly

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

A. To hold the same speed when going down a grade

B. Whenever the vehicle is parked

C. As little as possible

D. Only during pre and post trip inspections

. Whenever the vehicle is parked

110. The brake pedal in an air brake system:

A. Can be used as a foot rest during normal driving

B. Controls the speed of the air compressor

C. Controls the air pressure applied to put on the brakes

D. Is connected to the slack adjusters by rods & linkages

C. Controls the air pressure applied to put on the brakes

111. If your truck or bus has dual parking control valves it means that you can use pressure from a separate tank to:

A. Balance the service brake system

B. Release the spring brakes to move a short distance

C. Stay parked without using service pressure

D. Apply more brake pressure if the main supply is getting low

B. Release the spring brakes to move a short distance

112. A straight truck or bus air brake should not leak at a rate of more than ___ psi per minute with the engine off & brakes released.

A. 4 psi

B. 1 psi

C. 2 psi

D. 3 psi

C. 2 psi

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

A. Reduce the rick of ice in the air brake valves in cold weather

B. Eliminate the need for daily draining

C. Rid the wet tank of alcohol that settles at the bottom

D. Boost tank pressure the same way the super charger boost

A. Reduce the rick of ice in the air brake valves in cold weather

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

A. Use the full power of the brakes so that you can lock them

B. Can steer hard while braking hard

C. Stay in a straight line & steer

D. Use the hand brake first

C. Stay in a straight line & steer