Exam 55: Air-Conditioning Diagnosis and Service

Technician A always wears safety glasses when working on air-conditioning systems. Technician B makes sure there are no open flames in the area prior to working on the A/C system. Who is correct?

Explain how the Schrader valves are opened when the R134a manifold gauge hoses are connected to the A/C service fittings.

The EPA-approved certification exam on refrigerant recovery and recycling is administered by _____.

A sight glass is normally found on systems using R-134a and an orifice tube.

R-134a systems use synthetic ____________________ oils.

Technician A says the presence of oil around a fitting of an air-conditioning line may indicate an oil leak but not a refrigerant leak. Technician B says using an electronic leak detector is the best way to find the source of a refrigerant leak. Who is correct?

Technician A says pinhole leaks in the evaporator may be caused by acid formed when water and refrigerant are mixed. Technician B says leaks are most often found at hose connections and at the various fittings and joints in the system. Who is correct?

When is a manifold gauge set used?

Technician A says evacuating (pumping down) an air-conditioning system removes air and moisture from the system. Technician B says evacuating (pumping down) an air-conditioning system must be done anytime the system has been opened for repairs. Who is correct?

According to Section 609 of the Federal Clean Air Act, no one repairing or servicing a motor vehicle's A/C system can do so unless that person is properly trained and certified.

Technician A says the suction line connected to the compressor should be cool to the touch. Technician B says the discharge line from the compressor to the condenser should be hot along its entire length. Who is correct?

Why must moisture be removed from the A/C system during servicing?

What methods are commonly used to locate refrigerant leaks?

Why is cleanliness important when servicing an A/C system?

Technician A uses the ohmmeter function of a DMM [digital multimeter] to test the resistor block for opens. Technician B tests the resistor block with a lab scope. Who is correct?

Some cabin air filter elements are impregnated with baking soda and a filter with a biocidal cartridge. Both prevent the growth of bacteria, mold, mildew, algae, and yeast.

Before recovering refrigerant, the refrigerant must be _____.

The high- and low-pressure fittings must be changed during an R-12 to R-134a conversion.

Temperature/pressure charts are not required when manifold gauges are used in A/C performance testing.

A technician is trying, without success, to connect a 30-pound container of R-12 to his R-134a manifold gauge set. Technician A says the R-12 fitting is female and the gauge set fitting is also female. Technician B says the R-134a manifold gauge set uses a half-inch Acme thread, whereas the R-12 tank fitting has a standard thread. Who is correct?