310S Heating, Ventilation and Air Conditioning (HVAC) 2

Question 1

When diagnosing an A/C system with manifold gauges, what should be done FIRST to ensure accurate readings?

Accepted Answer

Run the engine and A/C system for 10 minutes to stabilize conditions

Answer

Running the engine and A/C for 10 minutes allows the system to reach stable operating conditions, ensuring accurate and comparable manifold gauge readings.

Question 2

Both the high-side and low-side pressures are higher than normal specifications. This MOST likely indicates:

Accepted Answer

System overcharge or restricted condenser airflow

Answer

High pressures on both sides indicate the condenser cannot dissipate heat efficiently due to blocked airflow, damaged fins, or the system is overcharged with refrigerant.

Question 3

Before opening an A/C system component for replacement, the technician MUST:

Accepted Answer

Recover the refrigerant using certified recovery equipment

Answer

Federal and provincial regulations require all refrigerant to be recovered using certified equipment before opening any A/C system component.

Question 4

After replacing an A/C system component, what is the main purpose of evacuating the system with a vacuum pump?

Accepted Answer

To remove air and moisture from the system

Answer

Evacuation removes non-condensable air and moisture, which could cause corrosion, acid formation, and ice blockage in the expansion device.

Question 5

What vacuum level should be achieved when evacuating an A/C system to ensure adequate moisture removal?

Accepted Answer

500 microns (0.5 mm Hg) or lower

Answer

Pulling the system to 500 microns or below causes moisture to boil off at ambient temperature and be removed by the vacuum pump, preventing contamination.

Red Seal Auto Tech 310S Practice Test

Red Seal Auto Tech 310S Practice Test

310S Heating, Ventilation and Air Conditioning (HVAC) 2