Exam 65: Heating and Air-Conditioning System Service

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

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?

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?

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

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

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

Safety glasses are worn whenever servicing AC components.

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?

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

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

What is the purpose of evacuating the AC system?

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?

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?

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?

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

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?

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?

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

Which of these is a non-condensable gas?

O-rings are usually made from ________.