Exam 55: Heating and Air Conditioning Diagnosis and Service

Technician A says all the refrigerant oil in the A/C system is contained inside the compressor. Technician B says the oil circulates throughout the entire A/C system and at any given moment each component holds a small amount of oil. Who is correct?

What should you do if you suspect that an alternative refrigerant has been used in the A/C system?

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

R-134a is stored in yellow containers.

What is the function of the low-pressure cutoff switch?

Why is it important to keep the manifold gauge set high-side hand valve closed while the system is running?

The A/C compressors on hybrid vehicles have _____colored wires and wire harness covers to indicate they carry high voltage.

It is acceptable to mix refrigerants in a vehicle's A/C system.

What should always be done before disconnecting a refrigerant connection?

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

Technician A says refrigerant hoses can be repaired. Technician B says damaged refrigerant hoses cannot be repaired and must be replaced. Who is correct?

What device does a computer-controlled A/C system use to monitor system pressure?

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

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?

Warm underhood temperatures produce lower than normal A/C system pressures.

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?

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?

Which of the following steps is recommended when converting an R-12 system to R-134a?

Technician A says if the suction line to the compressor is covered with thick frost, this might indicate that the expansion valve is flooding the evaporator. Technician B says the formation of frost on the outside of a line or component means there is a restriction to the flow of refrigerant. Who is correct?

The high-voltage electrical system of a hybrid vehicle should be shut down and isolated from the vehicle prior to working on the A/C compressor.