CFC Automotive Air Conditioning Service 3 — Questions and Answers
Question 1: A technician notices oil streaks near the compressor shaft seal of an R-134a system. This most likely indicates:
- Normal lubrication seepage
- A refrigerant and oil leak requiring repair (Correct answer)
- Condensation from normal operation
- An overcharged system
Correct answer: A refrigerant and oil leak requiring repair
Oil streaks at the compressor shaft seal indicate refrigerant is escaping along with compressor oil, requiring seal replacement.
Question 2: What is the purpose of the orifice tube in an automotive A/C system?
- To compress the refrigerant
- To metering refrigerant flow into the evaporator (Correct answer)
- To remove moisture from the refrigerant
- To condense refrigerant vapor into liquid
Correct answer: To metering refrigerant flow into the evaporator
The orifice tube is a fixed metering device that restricts refrigerant flow into the evaporator, causing pressure drop and cooling.
Question 3: When should a technician replace the receiver-drier or accumulator?
- Only when it leaks externally
- Whenever the system is opened for more than 30 minutes (Correct answer)
- Only when refrigerant is added
- Every 5 years regardless of service
Correct answer: Whenever the system is opened for more than 30 minutes
The desiccant in receiver-driers and accumulators absorbs moisture from the air when the system is opened, so replacement is recommended whenever the system is opened for an extended period.
Question 4: Which refrigerant is classified as an HFO (hydrofluoroolefin) and is approved for use in new automotive A/C systems?
- R-12
- R-134a
- R-1234yf (Correct answer)
- R-22
Correct answer: R-1234yf
R-1234yf is an HFO refrigerant with a very low GWP that has largely replaced R-134a in new vehicles since 2014.
Question 5: A technician uses refrigerant identifier equipment before servicing a vehicle A/C. The identifier shows 5% air contamination. The technician should:
- Proceed with recovery and service normally
- Recover the refrigerant into a separate dedicated cylinder and not mix it with pure refrigerant (Correct answer)
- Vent the system to atmosphere and recharge
- Add more refrigerant to dilute the contamination
Correct answer: Recover the refrigerant into a separate dedicated cylinder and not mix it with pure refrigerant
Contaminated refrigerant must be recovered into a dedicated cylinder and sent to a reclaimer — it cannot be mixed with pure refrigerant.
Question 6: Which condition would cause an automotive A/C system to have high pressure on both high and low sides?
- Low refrigerant charge
- Plugged expansion valve or orifice tube
- Faulty compressor
- Refrigerant overcharge or condenser airflow restriction (Correct answer)
Correct answer: Refrigerant overcharge or condenser airflow restriction
High pressures on both sides indicate too much refrigerant in the system or insufficient heat rejection at the condenser.
Question 7: Under EPA Section 609, records of refrigerant purchases for MVAC service must be kept for:
- 1 year
- 2 years
- 3 years (Correct answer)
- 5 years
Correct answer: 3 years
EPA Section 609 requires technicians and shops to keep records of refrigerant purchases for a minimum of three years.
CFC Automotive Air Conditioning Service 3
A technician notices oil streaks near the compressor shaft seal of an R-134a system.
This most likely indicates: