Refrigeration system component diag and repair

Question 1

65. Both pressure gauge needles are oscillating rapidly. Which component is the most likely cause?
    a. compressor (reed valves)
    b. Orifice tube (clogged)
    c. expansion valve (stuck closed)
    d. drier (desiccant bag is saturated with moisture)

Answer 1

a

Question 2

66. A noisy compressor is being discussed. Tech A says that the A/C system could be low on lubricating oil. Tech B says that the system could be overcharge. Which tech is correct?

Answer 2

c

Question 3

67. A FWD vehicle has a broken condenser line. What other vehicle component may also be defective that could have caused the condenser line to break?
    a. shock absorber
    b. engine mount
    c. cooling fan
    d. A/C compressor drive belt

Answer 3

b

Question 4

68. Two techs are discussing the replacement of an A/C compressor clutch. Tech A says that the air gap should be adjusted. Tech B says the front compressor seal should also be replaced when replacing the clutch assembly. Which tech is correct?

Answer 4

a

Question 5

69. Tech A says that the A/C compressor should operate when the controls are set to the heat position. Tech B says the A/C compressor should operate when the controls are set to the defrost position. Which tech is correct?

Answer 5

b

Question 6

70. The A/C compressor clutch does not engage when the A/C mode is selected and engine is running. Tech A says that the system may be low on refrigerant. Tech B says the low pressure switch may be electrically open. Which tech is correct?

Answer 6

c

Question 7

71. An A/C compressor is noisy when the clutch is engaged. Tech A says that the drive belt may be defective. Tech B says the compressor may be defective. Which tech is correct?

Answer 7

c

Question 8

72. An oily area is discovered around the front clutch assembly of the A/C compressor. Tech A says that the clutch is defective. Tech B says the compressor seal could be leaking. Which tech is correct?

Answer 8

b

Question 9

73. Tech A says that some refrigerant oil should be added to a replacement condenser to make sure that the system has the correct amount of oil. Tech B says that a specified viscosity o oil must be used to ensure proper lubrication of the compressor. Which tech is correct?

Answer 9

c

Question 10

74. A condenser is being flushed. Tech A says that the old refrigerant oil can be mixed with and disposed of with used engine oil. Tech B says that the specified refrigerant oil should be added to the new condenser. Which tech is correct?

Answer 10

b

Question 11

75. Tech A says that if an evaporator has been replaced, 2 or 3 ounces of refrigerant oil should be added to the system. Tech B says that the old evaporator should be drained and the oil measured to determine how much oil to add when installing the replacement evaporator. Which tech is correct?

Answer 11

a

Question 12

76. Two techs are discussing orifice tubes. Tech A says the inlet screen should be installed facing the evaporator inlet. Tech B says the inlet screen should be facing toward the condenser section of the system. Which tech is correct?

Answer 12

b

Question 13

77. Tech A says that all HFC-134a systems use the same refrigerant oil. Tech B says that refrigerant oil, regardless of type, must be kept in a sealed container to keep it from absorbing moisture from the air. Which tech is correct?

Answer 13

b

Question 14

78. Refer to book

Answer 14

d

Question 15

79. Refer to book

Answer 15

b

Question 16

80. Refer to book

Answer 16

d

Question 17

81. Refer to book

Answer 17

c

Question 18

82. A compressor is being replaced. Tech A says that the oil should be drained from the old compressor and measured so that the same amount of oil can be installed in the replacement compressor unless it is shipped with oil. Tech B says the drained oil should be installed in the new compressor to make sure that it is lubricated with the correct oil. Which tech is correct?

Answer 18

a

Question 19

83. The capillary tube on the expansion valve has been bent shut as a result of a collision. Tech A says the expansion valve should be replaced. Tech B says that only the capillary tube needs to be replaced. Which tech is correct?

Answer 19

a

Question 20

84. An automotive A/C refrigerant system has been disconnected for several months and is now being returned to service. Tech A says that the reviver drier or accumulator should be replaced. Tech B says the system should be flushed and fresh refrigerant oil should be installed before evacuating and recharging the system. Which tech is correct?

Answer 20

a

Question 21

85. A leaking evaporator is being replaced. Tech A says that 2 or 3 ounces of oil should be added to the new evaporator to allow for the amount that is trapped in the old evaporator. Tech B says that the condensate drain hole should be checked to see that it is open before completing the repair. Which tech is correct?

Answer 21

c

Question 22

86. A compressor clutch does not engage even when a jumper wire is connected directly to the compressor connection. An ohmmeter check of the compressor clutch coil results in a reading of 14.7 k ohms. Tech A says the compressor clutch coil is okay and that the compressor itself is defective. Tech B says the compressor clutch coil is defective. Which tech is correct?

Answer 22

b

Question 23

87. A replacement compressor clutch is being installed. All of the following should be checked except _____
    a. air gap
    b. front seal leakage
    c. drive belt
    d. amount of refrigerant oil in the compressor

Answer 23

d

Question 24

88. A clogged orifice tube is being replaced. Tech A says that the specified orifice tube should be used as a replacement because the orifice size can vary among the manufacturers. Tech B says that orifice tubes are size by the outside diameter and that any orifice tube that fits will work okay. Which tech is correct?

Answer 24

a