ASE A7 Heating & Air Conditioning
Practice Exam Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
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1. What is the main purpose of the expansion valve in an automotive A/C
system?
A. Increase system pressure
B. Filter refrigerant
C. Regulate refrigerant flow into the evaporator
D. Heat the refrigerant
Rationale: The expansion valve controls the flow of refrigerant into the
evaporator to maintain proper cooling and prevent evaporator freezing.
2. Which refrigerant is most commonly used in modern automotive A/C
systems?
A. R-12
,B. R-134a
C. R-22
D. R-410A
Rationale: R-134a replaced R-12 due to environmental regulations and is
widely used in modern vehicles.
3. What is the typical operating pressure of an R-134a system at 70°F
ambient temperature?
A. 50–75 psi
B. 90–120 psi
C. 25–45 psi low side, 150–225 psi high side
D. 10–20 psi
Rationale: R-134a systems operate at low-side pressures around 25–45 psi
and high-side pressures around 150–225 psi at moderate temperatures.
4. What effect does a clogged condenser have on an A/C system?
A. Reduces airflow in the cabin
B. Increases high-side pressure and reduces cooling efficiency
C. Increases low-side pressure
D. Causes compressor over-speed
Rationale: A clogged condenser prevents proper heat dissipation, raising
high-side pressure and reducing overall cooling efficiency.
5. Which component stores refrigerant and removes moisture from the
system?
A. Evaporator
,B. Compressor
C. Receiver/drier
D. Condenser
Rationale: The receiver/drier stores liquid refrigerant and contains a
desiccant to remove moisture, protecting the system.
6. Which is a sign of a refrigerant leak?
A. Reduced engine power
B. Excessive oil consumption
C. Hissing sound near A/C components
D. Brake pedal vibration
Rationale: Leaks in the A/C system often produce audible hissing or
bubbling noises and reduce cooling performance.
7. What is the purpose of the compressor clutch?
A. Regulate refrigerant pressure
B. Engage and disengage the compressor as needed
C. Filter the refrigerant
D. Increase condenser efficiency
Rationale: The clutch allows the compressor to cycle on and off,
maintaining proper system operation and reducing wear.
8. Why is it important to evacuate an A/C system before charging?
A. To remove old refrigerant
B. To reduce oil contamination
C. To remove air and moisture
, D. To test the expansion valve
Rationale: Air and moisture reduce cooling efficiency and can damage
components, so evacuation is necessary before charging.
9. What could cause the evaporator to freeze?
A. Low refrigerant flow
B. High ambient temperature
C. Restricted airflow across the evaporator
D. Faulty condenser fan
Rationale: Restricted airflow reduces heat transfer, causing the evaporator
temperature to drop below freezing and ice to form.
10. What is the primary function of the condenser fan?
A. Increase cabin airflow
B. Lubricate compressor
C. Assist in heat dissipation from the condenser
D. Regulate refrigerant flow
Rationale: The condenser fan ensures sufficient airflow across the
condenser to release heat from the high-pressure refrigerant.
11. What does the term “superheat” refer to?
A. Refrigerant pressure above design limits
B. Compressor temperature
C. Temperature of refrigerant vapor above its boiling point in the
evaporator
D. Heat in the condenser
Practice Exam Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
1. What is the main purpose of the expansion valve in an automotive A/C
system?
A. Increase system pressure
B. Filter refrigerant
C. Regulate refrigerant flow into the evaporator
D. Heat the refrigerant
Rationale: The expansion valve controls the flow of refrigerant into the
evaporator to maintain proper cooling and prevent evaporator freezing.
2. Which refrigerant is most commonly used in modern automotive A/C
systems?
A. R-12
,B. R-134a
C. R-22
D. R-410A
Rationale: R-134a replaced R-12 due to environmental regulations and is
widely used in modern vehicles.
3. What is the typical operating pressure of an R-134a system at 70°F
ambient temperature?
A. 50–75 psi
B. 90–120 psi
C. 25–45 psi low side, 150–225 psi high side
D. 10–20 psi
Rationale: R-134a systems operate at low-side pressures around 25–45 psi
and high-side pressures around 150–225 psi at moderate temperatures.
4. What effect does a clogged condenser have on an A/C system?
A. Reduces airflow in the cabin
B. Increases high-side pressure and reduces cooling efficiency
C. Increases low-side pressure
D. Causes compressor over-speed
Rationale: A clogged condenser prevents proper heat dissipation, raising
high-side pressure and reducing overall cooling efficiency.
5. Which component stores refrigerant and removes moisture from the
system?
A. Evaporator
,B. Compressor
C. Receiver/drier
D. Condenser
Rationale: The receiver/drier stores liquid refrigerant and contains a
desiccant to remove moisture, protecting the system.
6. Which is a sign of a refrigerant leak?
A. Reduced engine power
B. Excessive oil consumption
C. Hissing sound near A/C components
D. Brake pedal vibration
Rationale: Leaks in the A/C system often produce audible hissing or
bubbling noises and reduce cooling performance.
7. What is the purpose of the compressor clutch?
A. Regulate refrigerant pressure
B. Engage and disengage the compressor as needed
C. Filter the refrigerant
D. Increase condenser efficiency
Rationale: The clutch allows the compressor to cycle on and off,
maintaining proper system operation and reducing wear.
8. Why is it important to evacuate an A/C system before charging?
A. To remove old refrigerant
B. To reduce oil contamination
C. To remove air and moisture
, D. To test the expansion valve
Rationale: Air and moisture reduce cooling efficiency and can damage
components, so evacuation is necessary before charging.
9. What could cause the evaporator to freeze?
A. Low refrigerant flow
B. High ambient temperature
C. Restricted airflow across the evaporator
D. Faulty condenser fan
Rationale: Restricted airflow reduces heat transfer, causing the evaporator
temperature to drop below freezing and ice to form.
10. What is the primary function of the condenser fan?
A. Increase cabin airflow
B. Lubricate compressor
C. Assist in heat dissipation from the condenser
D. Regulate refrigerant flow
Rationale: The condenser fan ensures sufficient airflow across the
condenser to release heat from the high-pressure refrigerant.
11. What does the term “superheat” refer to?
A. Refrigerant pressure above design limits
B. Compressor temperature
C. Temperature of refrigerant vapor above its boiling point in the
evaporator
D. Heat in the condenser
