Deck 65: Heating and Air-Conditioning System Service

Question 1

A customer complains that the heater works sometimes, but sometimes only cold air comes out whileDriving. Technician A says that the water pump is defective. Technician B says that the cooling system could be low on coolant. Which technician is correct?

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

Answer 1

Technician B only

Question 2

Two technicians are discussing replacing heater hoses. Technician A says that the replacement hoses should be the same length as the original hoses. Technician B says that the replacement hoses should be cut as short as possible to allow more coolant to flow through the heater core faster. Which technician is correct?

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

Answer 2

Technician A only

Question 3

A defective thermostat can cause the engine to operate ________.

A)Too cold
B)Too hot
C)Either A or B
D)Neither A nor B

Answer 3

Either A or B

Question 4

O-rings are usually made from ________.

A)HSN
B)Natural rubber
C)Neoprene
D)Either A or C

Question 5

What type of service valves are used with R-134a?

A)Quick disconnect valves
B)Gate valves
C)Schrader valves
D)Saddle valves

Question 6

Which reading represents the lowest vacuum reading?

A)28 in. Hg
B)27 in. Hg
C)29 in. Hg
D)500 microns

Question 7

Which of these is a non-condensable gas?

A)R-134a
B)Air
C)Ozone
D)R-12

Question 8

Technician A says that all orifice tubes on all vehicles use the same size orifice size. Technician B says that orifice tubes vary the orifice size by application. Which technician is correct?

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

Question 9

Which part MUST be used when refitting a vehicle from R-12 to R-134a refrigerant?

A)A new condenser
B)A high pressure cutoff switch
C)A new service fitting and a retrofit label
D)Both B and C

Question 10

When replacing a compressor clutch, what is the critical measurement?

A)Voltage drop
B)High-pressure pressure
C)Air gap
D)Current draw

Question 11

Technician A says that the system should be vacuumed out so that all the old oil is removed. Technician B says that system evacuation (vacuuming) is done to remove moisture from the system. Which technician is correct?

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

Question 12

Technician A says to charge the system with refrigerant until the condenser temperature is equal to the ambient temperature plus 100 deg. F. Technician B says to charge the system with a manufacturer specified weight of refrigerant. Which technician is correct?

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

Question 13

When replacing an air conditioning component, all of the following are true about the refrigerant oil EXCEPT ________.

A)The old oil should be drained from the component and measured
B)The old oil should be replaced with fresh oil
C)The oil removed during refrigerant recovery should be measured
D)The oil charge stamped on the compressor should be added to the system

Question 14

During a retrofit, the replacement R-134a charge should be ________ than the specified R-12 charge.

A)20-30% more
B)20-30% less
C)10-20% less
D)10-20% more

Question 15

What is the purpose of evacuating the AC system?

A)To eliminate any moisture inside the system
B)To remove any foreign substances inside the system
C)Both A and B are correct
D)Neither A nor B is correct

Question 16

Technician A says a refrigerant identifier is only needed when the technician is unsure of the refrigerant used in an AC system. Technician B says some refrigerant identifiers can measure the amount of moisture in the refrigerant system to aid in diagnosis. Who is correct?

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

Question 17

Which of the following must always be replaced when a retrofit is performed?

A)Expansion valve
B)Compressor
C)Refrigerant oil
D)Condenser

Question 18

Two technicians are discussing how to remove refrigerant from a system. Technician A says that you can vent it into the atmosphere as long as it has moisture in it. Technician B says that all refrigerant must be captured. Who is correct?

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

Question 19

Technician A says that vacuum is usually measured in psi. Technician B says vacuum is usually measured in inches of mercury (Hg). Who is correct?

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

Question 20

When replacing a failed compressor, it is also a good idea to ________.

A)Install an in-line filter
B)Flush the system
C)Replace the accumulator
D)All of these

Question 21

The radiator usually cools better if the front air cam is removed.

Question 22

If a condenser has a leak it can be easily repaired with epoxy.

Question 23

Safety glasses are worn whenever servicing AC components.

Question 24

The service valve cores are normally removed before evacuating the system.

Question 25

A micron gauge is a better indicator of vacuum and a gauge calibrated in in. Hg.