Deck 6: Refrigerant System Servicing and Testingair-Conditioning System Servicing and Testing

Question 1

Most original equipment manufacturers use what type of lubricant in their R-134a systems?

A) Mineral
B) Ester
C) Paraffinc
D) PAG

Answer 1

C

Question 2

When the air conditioning system is operating,the suction line should feel hot to the touch.

Answer 2

False

Question 3

When the air conditioning system is operating,the discharge line should feel hot to the touch.

Answer 3

True

Question 4

Technician A says that the evacuation process will remove dirt and debris from the refrigerant system.Technician B says that the evacuation process will remove moisture and air from the refrigerant system.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 5

The pressure of the bulk recovery tank can be tested to identify refrigerant cross contamination.

Question 6

A leak may be marked by the presence of refrigeration oil.

Question 7

Technician A says a soap solution must be used in well-ventilated spaces only.Technician B says leaks often occur in areas of limited access where it is difficult to use a halogen leak detector.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 8

R-134a and R-12 systems use the same refrigerant oil.

Question 9

All of the following statements about system evacuation are true,EXCEPT:

A) Water boils at a lower temperature at higher altitudes.
B) Vacuum pump efficiency is increased at higher altitudes.
C) At high altitudes, ambient temperature must be raised for the vacuum pump to efficiently remove moisture.
D) Running the vehicle engine will raise the temperature of the underhood components.

Question 10

Refrigeration oil circulates with the refrigerant through the system.

Question 11

An air conditioning system should be pumped down (evacuated)for a minimum of ____ minutes.

A) 10
B) 20
C) 30
D) 60

Question 12

R-134a is more likely to absorb moisture than R-12.

Question 13

The electronic (halogen)leak detector is the most expensive and sensitive of all leak detection devices.

Question 14

A fluorescent leak detector will only work after a special dye is injected into the system.

Question 15

Technician A says that the electronic leak detector probe should be held directly against a suspected leak area during a eak test.Technician B says that the electronic leak detector requires routine calibration and probe tip inspection and maintenance.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 16

Refrigerant vapors are lighter than air.

Question 17

All of the following statements about injecting a dye solution into the air conditioning system are true,EXCEPT:

A) Dye is approved for automotive air conditioning system use.
B) The dye affects the overall performance of the system.
C) Dye is available in either yellow or red.
D) A few days after injection, the dye will be visible at the point of the leak.

Question 18

When making system repairs,install the receiver-drier or accumulator

A) first.
B) last.
C) after evacuating the system.
D) any time.

Question 19

Technician A says the performance test is a way of measuring system pressures.Technician B says the performance test is a way of measuring the outside humidity.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 20

System malfunctions cannot be detected by visual inspection.

Question 21

Technician A says that the A/C system may be charge through the LOW side when the system is operating.Technician B says that the A/C system may be charged through the HIGH side when the system is off .Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 22

Technician A says a refrigerant is considered contaminated if the refrigerant contains greater than 2 percent of foreign material(s).Technician B says moisture and air reduce the system's efficiency and are considered foreign material or contaminants.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 23

When servicing a Hybrid vehicles refrigerant system it is imperative that the correct what be used in the refrigerant system?

Question 24

Technician A says "intent to vent" means the technician is working in a shop without adequate ventilation.Technician B says "intent to vent" means the technician is working on an air conditioner in a shop that does not have a recovery machine for each type of refrigerant being serviced.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 25

Technician A says any kind of refrigerant can be added to the system for leak testing.Technician B says it is not necessary to purge the hose between the refrigerant container and gauge manifold when adding refrigerant for leak testing.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 26

Charging the system is being discussed.Technician A says the refrigerant must be weighed (or metered)to obtain a proper charge.Technician B says overcharging the system will reduce its cooling efficiency.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 27

Technician A says the manifold and gauge set is an important diagnostic tool.Technician B says the manifold and gauge set is an important tool for evacuating and charging the system.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 28

A technician is checking the evaporator for leaks on an R-134a refrigerant system.Technician A says that it is acceptable to use shop air to pressurize the system and use an electrnic microphone to listen for leakage.Technician B says that it is acceptable to charge the system with R-134a and then insert the elctronic leak detector probe in the evaporator drain.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 29

Many pieces of air conditioning service equipment can do all of the following,EXCEPT:

A) refrigerant recovery.
B) refrigerant recycling.
C) refrigerant reclaiming.
D) system evacuation.

Question 30

Refrigerant analyzers or identifiers are being discussed.Technician A says if the analyzer displays "R-134a," then the refrigerant is 98 percent pure.Technician B says if "HC" is displayed,then the refrigerant is flammable.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 31

Technician A says that the recommended oil for most R-134a systems is PAG oil.Technician B says that the recommended oil for R-12 systems is mineral-based oil.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 32

Dye leak detectors are being discussed.Technician A says injection dye will be visible after a few days of system operation if a leak is present.Technician B says a special lamp is required to locate a leak with fluorescent dye.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 33

During initial system evaluation an unknown refrigerant is identified.Which of the following should a technician do:

A) Treat it as a contaminated refrigerant.
B) Purge it into the atmosphere
C) Treat it like R-12 and recover and recycle it.
D) Treat it like R-134a and recover and recycle it.

Question 34

What is meant by purging an air conditioning system?

Question 35

Technician A says recycled refrigerant in portable storage containers should be periodically shecked for noncondensable gas contamination.Technician B says contaminated refrigerant will not affect system performance..Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 36

What is formed when refrigerants react chemically with water?

Question 37

What is the purpose of system evacuation?

Question 38

A technician determined that all the refrigerant had leaked out of the A/C system.Technician A says that the low-pressure switch will need to be replaced before the the system can be recharged.Technician B says that the low pressure switch will need to be adjusted before the system can be recharged.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 39

What two factors determine the amount of moisture removed from an air conditioning system?

Question 40

An inoperative cooling fan may cause high head (high-side)pressure at what vehicle speeds?

A) idle (vehicle not in motion)
B) slow
C) highway
D) both A and B

Question 41

Explain the difference between refrigerant recovery,reclaiming,and recycling.

Question 42

List popular methods of refrigerant leak detection.

Question 43

When evacuating the system,what position should all service valves and manifold gauge valves be in?

Question 44

While checking the compressor drive belt for proper tension,also check the belt for what other flaws?

Question 45

Explain why leaks at the service ports are often missed.

Question 46

What are the sources of refrigerant system contamination?

Question 47

Explain why recharging the air conditioning system is the most important service procedure the technician will perform on the system.

Question 48

Define hot and cold refrigerant leaks.

Question 49

Explain when a soap solution should be used as a method of leak detection.

Question 50

What is the minimum time a system should be evacuated for?

Question 51

What is the most efficient device for removing moisture from a refrigerant system?