AC Recharge

This procedure covers evacuating, leak testing, and recharging the R-1234yf air conditioning system on the 2023 Chevrolet Bolt EUV electric vehicle to restore proper cooling performance.

Warnings

Tools required

Parts

• R-1234yf refrigerant × 1 — Use OEM specification
• PAG 46 oil (EV compressor compatible) × 1 — Use OEM specification
• AC service port caps × 2 — Use OEM specification

Preparation

1. Verify the vehicle is in Park with the 12V battery disconnected to prevent inadvertent HVAC system activation
2. Ensure the work area is well-ventilated and free from open flames or ignition sources
3. Locate the low-pressure service port (larger diameter, typically on the accumulator) and high-pressure service port (smaller diameter, typically on the liquid line near the condenser)
4. Inspect all visible AC lines, condenser, and evaporator housing for obvious signs of damage or oil residue indicating leaks
5. Connect the AC recovery/recharge machine to a power source and verify it is calibrated for R-1234yf refrigerant

Procedure

1. 1

   Connect recovery equipment
   Remove the caps from both the low-pressure and high-pressure service ports. Attach the blue (low-pressure) hose from the manifold gauge set to the low-pressure service port and the red (high-pressure) hose to the high-pressure service port. Ensure connections are secure and hand-tight.
2. 2

   Recover existing refrigerant
   Start the recovery machine and allow it to completely evacuate all R-1234yf refrigerant from the system. Monitor the recovery process until the machine indicates recovery is complete and no refrigerant remains. The machine will automatically measure and display the amount of refrigerant recovered. Record this amount for comparison to system capacity specifications (approximately 18-20 oz for the Bolt EUV).
3. 3

   Perform leak test
   With the system evacuated, close all manifold valves. Introduce a small amount of nitrogen (maximum 50 psi) or use the leak detection mode on your equipment. Use an electronic leak detector or UV light (if UV dye was previously added) to check all connections, service ports, condenser, evaporator lines, and compressor fittings. If leaks are detected, repair them before proceeding. This procedure assumes no major leaks requiring component replacement.
4. 4

   Evacuate the system
   Connect the vacuum pump to the center port of the manifold gauge set. Open both the low and high-pressure valves on the manifold. Start the vacuum pump and evacuate the system to a deep vacuum of at least 500 microns. Maintain this vacuum for a minimum of 30 minutes to remove all air and moisture from the system. This step is critical for proper AC performance and compressor longevity.
5. 5

   Perform vacuum hold test
   After evacuating for 30 minutes, close both manifold valves and shut off the vacuum pump. Monitor the system vacuum for 10 minutes. The vacuum reading should remain stable (not rise more than 500 microns). If vacuum rises significantly, there is a leak that must be repaired before recharging.
6. 6

   Add compressor oil
   Calculate the required PAG 46 oil quantity. If the system was completely empty or lost significant refrigerant, add the amount of oil that was removed during recovery (the machine displays this) plus any additional oil lost through component replacement. For a standard recharge with no component replacement, add approximately 1-2 oz of EV-compatible PAG 46 oil through the low-pressure port using the recharge machine's oil injection function.
7. 7

   Charge the system
   With the vacuum still holding, connect the R-1234yf refrigerant supply to the recharge machine. Program the machine for the correct refrigerant amount (18-20 oz, verify exact specification on the underhood label). Begin charging through the low-pressure side with the engine OFF (electric compressor will not run until system pressure is adequate). Monitor the recharge process until the specified amount has been added.
8. 8

   Reconnect 12V battery and test system
   Reconnect the 12V battery. Start the vehicle and turn the AC system to MAX cooling with the blower on high speed. Allow the system to run for at least 5 minutes. Monitor the low-pressure gauge (should read 25-40 psi) and high-pressure gauge (should read 150-250 psi depending on ambient temperature). Use a thermometer to measure the center vent outlet temperature, which should be 35-45°F with ambient temperature around 70-80°F.
9. 9

   Final leak check
   With the system running, perform a final leak check at all service ports, connections, and fittings using the electronic leak detector. Pay special attention to the service port connections. If no leaks are detected, turn off the vehicle and carefully disconnect the manifold gauge set from both service ports.
10. 10

    Install service port caps
    Immediately install new service port caps on both the low and high-pressure ports to prevent contamination and seal the system. Hand-tighten the caps securely.

Reassembly

1. Verify all service port caps are installed and hand-tight
2. Store all refrigerant recovery data and service records with the vehicle documentation
3. Clean any oil residue from service port areas with approved AC system cleaner

Verification

• Start the vehicle and run the AC system on MAX cooling for 10 minutes
• Verify center vent temperature is between 35-45°F with ambient temperature around 70-80°F
• Confirm the electric compressor cycles on and operates quietly without unusual noises
• Check that both low-pressure (25-40 psi) and high-pressure (150-250 psi) readings are within normal operating ranges
• Verify no refrigerant odor or visible oil leaks around service ports and connections
• Test all AC modes (MAX, normal, defrost) to ensure proper operation across all settings

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