ASE A7 Heating Air Conditioning Practice Test

1. During a visual inspection an oily spot is found on a hose leading from the compressor. Technician A says there may be a refrigerant leak in the system. Technician B says today's R134a systems use mineral oil instead of the older R12 compatible PAG oil. Who is correct?

  • A. Technician A
  • B. Technician B
  • C. Both A and B
  • D. Neither A or B

1.

Answer A is correct. Finding an oily spot on an A/C hose is a quick and easy way to spot a refrigerant leak. Closer inspection and testing will be necessary.

Answer B is wrong. Today's R134a air conditioning systems require PAG oil. Mineral oil is compatible with R12 refrigerant.

Answer C is wrong. Technician A is correct.

Answer D is wrong. Technician A is correct.

Snapshot of a scan tool display.

2. The inputs of a 134a refrigerant system in a passenger car are scanned. The display is shown above. Which of the following is correct?

  • A. The system has been overcharged with refrigerant.
  • B. The system has an undercharge.
  • C. The outside air temperature is preventing compressor clutch operation.
  • D. None of these statements are correct.

2.

Answer A is wrong. The ASE A7 Heating and Air Conditioning test has a few questions regarding control modules their circuits and any needed repairs. The system scan shown has an acceptable charge.

Answer B is wrong. The charge is sufficient.

Answer C is wrong. Most systems prevent compressor clutch operation when the temperature is in the thirties.

Answer D is correct. None of these are correct.

3. A refrigerant service station is used to recover, evacuate and recharge an air conditioning system. Technician A says the needle on the gauge should not increase and should remain steady after the recovery process is complete. Technician B says if the needle moves more than .01 inches of mercury after the evacuation process is complete, the system should be inspected for leaks. Who is correct?

  • A. Technician A
  • B. Technician B
  • C. Both A and B
  • D. Neither A or B

3.

Answer A is wrong. The needle should remain steady after recovery. If there’s an increase in pressure it's likely there’s refrigerant left in the system.

Answer B is wrong. After the evacuation process is complete, the system is allowed to rest a specified amount of time. If the needle moves, the system should be inspected for leaks.

Answer C is correct. Both Technicians are correct.

Answer D is wrong. Both Technicians are correct.

4. A vehicle has poor air conditioning performance. The customer has added R134a refrigerant to the system. Technician A says to use a refrigerant identifier. Technician B says refrigerant mixtures are not recommended, but will not affect system pressures. Who is correct?

  • A. Technician A
  • B. Technician B
  • C. Both A and B
  • D. Neither A or B

4.

Answer A is correct. Use a refrigerant identifier to identify R12, R134a, R22, hydrocarbons and air.

Answer B is wrong. This mixture increases the system's high pressure side, resulting in high head pressure. This causes premature compressor failure.

Answer C is wrong. Technician A is correct.

Answer D is wrong. Technician A is correct.

5. A squeal is heard only when the compressor clutch first engages. Technician A says this is caused by a loose serpentine belt. Technician B says this is caused by a worn clutch pulley bearing. Who is correct?

  • A. Technician A
  • B. Technician B
  • C. Both A and B
  • D. Neither A or B

5.

Answer A is correct. A loose serpentine belt will cause a squeal when the clutch first engages.

Answer B is wrong. A faulty pulley bearing would make a growling or squealing sound whenever the engine is running.

Answer C is wrong. Technician A is correct.

Answer D is wrong. Technician A is correct.