Deck 5: Refrigerant System Componentsservicing System Components

Question 1

The EPA requires the replacement of hoses or seals during the retrofit of a vehicle from R-12 to R-134a.

Answer 1

False

Question 2

The correct oil for use with R-134a is mineral oil.

Answer 2

False

Question 3

If a system has a thermostatic expansion valve,it will also have all of the following parts,EXCEPT:

A) accumulator.
B) compressor.
C) condenser.
D) receiver-drier.

Answer 3

A

Question 4

The expansion valve regulates the evaporator temperature based on the thermal heat load it detects.

Question 5

Technician A says that the thermostatic expansion valve may be located anywhere between the evaporator outlet and the compressor inlet.Technician B says that fixed orifice tubes sizes are interchangeable in order to taylor system performance.Who is correct?

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

Question 6

Technician A says the amount of refrigerant flowing through an orifice tube is controlled by a remote sensing bulb.Technician B says the orifice tube is located in the liquid line between the condenser outlet and evaporator inlet.Who is correct?

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

Question 7

Technician A says a receiver-drier is used in systems with a fixed orifice tube.Technician B says the receiver-drier stores reserve refrigerant.Who is correct?

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

Question 8

An H valve is often referred to as a block valve.

Question 9

Most vendors will not honor the warranty on a new or rebuilt compressor unless the ____ is replaced at the time of service.

A) accumulator
B) receiver-drier
C) expansion valve
D) a or b

Question 10

Tubing with a nylon lining can be used with both R-12 (CFC-12)and R-134a (HFC-134a)refrigerants.

Question 11

Most early R-12 hoses were not barrier hoses.

Question 12

The term purge an air-conditioning system in general terms means to:

A) Add sealant to the refrigerant system
B) Recharge the refrigerant system
C) Flush the refrigerant system.
D) Remove the refrigerant from the system.

Question 13

Before attempting to service an automotive air-conditioning system consider all of the following Except:

A) Can customer afford the repair?
B) Do you have the proper tools and equipment to service the system?
C) Listen to customer complaint.
D) Does your diagnosis make sense based on customer complaint.

Question 14

Removing spring lock fittings on refrigerant lines requires a special tool.

Question 15

Before installation: Technician A says that refrigerant system O-rings should be coated with new refrigerant oil.Technician B says refrigerant system O-rings can be coated with a gasket sealant.Who is correct?

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

Question 16

All of the following are reasons why a flooded evaporator will not cool well,EXCEPT:

A) High pressure in the evaporator prevents refrigerant vaporization.
B) There is no room for expansion.
C) The refrigerant vaporizes too quickly.
D) The refrigerant cannot take on heat.

Question 17

O-rings will not usually leak if they are reused.

Question 18

The compressor separates the low side from the high side of the system.

Question 19

Refrigerant enters the compressor as a

A) high-pressure vapor.
B) low-pressure vapor.
C) low-pressure liquid.
D) high-pressure liquid.

Question 20

If the evaporator is starved,superheat is very high.

Question 21

What type of desiccants are acceptable for use on R-134a systems?

Question 22

What effect will bent cooling fins on the condenser have on the refrigerant system?

Question 23

Why is the remote bulb of a thermostatic expansion valve attached with insulated tape to the refrigerant line?

Question 24

Define desiccant.

Question 25

What is meant by the term starved evaporator?

Question 26

The refrigerant from a vehicles A/C system is being recovered into a recovery unit.Technician A says that both the vapor and liquid tank valves on the recovery unit should be OPEN.Technician B says that both the high-side and low-side gauge valves on the manifold and gauge set should be OPEN.Who is correct?

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

Question 27

Desiccant is being discussed.Technician A says both manufacturer-approved refrigerants use the same desiccant.Technician B says the desiccant in an accumulator can be replaced without replacing the accumulator.Who is correct?

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

Question 28

Technician A says in an H-block valve the temperature sensing sleeve (bulb)is internally located in the outlet port of the valve.Technician B says the operation and function of the H-valve,or block valve,are essentially the same as the thermostatic expansion valve (TXV).Who is correct?

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

Question 29

Once the refrigerant from the air conditioning system has been recovered,which of the following should the technician do?

A) Check the purity of the refrigerant in the recovery tank.
B) Change the recovery unit fiters.
C) Record the amount of refrigerant oil removed from the system.
D) Change the receiver-drier.

Question 30

Define heat load.

Question 31

A flooded evaporator can cause damage to the

A) compressor.
B) condenser.
C) expansion valve.
D) receiver-drier.

Question 32

On an expansion valve system the valve opens and closes in relation to ______ temperature and pressure.

A) compressor
B) evaporator
C) accumuator
D) any of the above, depending on the manufacturer

Question 33

What is the purpose of the evaporator?

Question 34

Describe what happens to the refrigerant within the evaporator.

Question 35

Technician A says there are several condenser designs and flow paths in use today.Technician B says the only flow paths for refrigerant through the condenser's tubing is the parallel cross flow.Who is correct?

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

Question 36

A leaking evaporator is being replaced.Technician A says the new o-rings should be coated with clean refrigerant oil.Technician B says the some refrigerant oil shoud be added to the system prior to recharging the system.Who is correct?

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

Question 37

Refrigerant leaves the evaporator as a

A) high-pressure vapor.
B) low-pressure vapor.
C) low-pressure liquid.
D) high-pressure liquid.

Question 38

If the refrigerant system is suspected of being contaminated with moisture what component should also be replaced?

Question 39

Why must the condenser outlet be at the bottom?

Question 40

Describe the two major functions of the air conditioning system compressor.

Question 41

What is the function of the evaporator case drain vent?

Question 42

What is a barrier hose and when must one be used?

Question 43

What is the function of the orifice tube?

Question 44

What is a flooded evaporator and how does it occur? What are the results of this condition?