This procedure covers recharging the AC refrigerant system on a 2014-2019 Toyota Corolla with the 1.8L I4 engine using proper equipment and refrigerant specifications.

Warnings

Tools required

Parts

• R-134a refrigerant × 1 — Use OEM specification
• PAG oil (ND-11) × 1 — Use OEM specification
• AC service port caps × 2 — Replace if damaged

Preparation

1. Park vehicle on level surface and engage parking brake
2. Start engine and allow to reach normal operating temperature
3. Turn AC system to MAX COLD and high fan speed for 5 minutes to verify compressor operation
4. Turn off engine and allow to cool for 10 minutes
5. Locate low-side (blue cap) and high-side (red cap) service ports on AC lines near firewall

Procedure

1. 1

   Connect recovery equipment
   Remove caps from both AC service ports. Connect the refrigerant recovery machine's blue hose to the low-side port and red hose to the high-side port. Ensure all connections are secure to prevent refrigerant loss during recovery.
2. 2

   Recover existing refrigerant
   Follow recovery machine manufacturer's instructions to recover all refrigerant from the system. Allow machine to run until recovery is complete, typically indicated by system pressure reaching vacuum. Note the amount of refrigerant recovered for reference.
   ⚠️Never disconnect hoses while system is pressurized. Always verify pressure is at zero before disconnecting.
3. 3

   Perform vacuum test
   Connect AC vacuum pump to manifold gauge set. Open both manifold valves and run vacuum pump for minimum 30 minutes to achieve at least 29 inches of mercury vacuum. Close manifold valves, turn off pump, and monitor gauges for 15 minutes. System should hold vacuum with no more than 2 inches pressure rise, confirming no leaks.
   ⚠If system does not hold vacuum, there is a leak that must be repaired before recharging.
4. 4

   Add PAG oil if necessary
   If compressor was replaced or significant oil was recovered, add appropriate amount of ND-11 PAG oil through low-side port using oil injector. For routine recharge, add 1 oz (30ml) to replace oil lost during recovery. Toyota specifies total system capacity of 4.7 oz (140ml) PAG oil.
5. 5

   Prepare refrigerant charge
   Place R-134a refrigerant container on electronic scale and zero the scale. Connect charging hose to refrigerant container. Purge air from charging hose by briefly opening the valve until refrigerant flows, then close valve. Connect charging hose to low-side port on manifold gauge set.
6. 6

   Charge system with engine off
   With engine off, open low-side valve on manifold gauge set and refrigerant container valve. Allow refrigerant to flow into system via vapor charging. Monitor scale and add approximately 12 oz (340g) or until low-side pressure reaches 50-60 psi. Close valves when target weight is reached.
7. 7

   Complete charge with engine running
   Start engine and set AC to MAX COLD with blower on HIGH. Compressor should engage. Slowly add remaining refrigerant through low-side port only while monitoring gauges. Add total of 16.2 oz (460g) refrigerant as indicated on scale. Low-side pressure should stabilize at 25-35 psi and high-side at 200-250 psi at ambient temperature of 75-85°F.
   ⚠Never charge through high-side port with engine running as this can cause liquid refrigerant to enter compressor and cause damage.
8. 8

   Verify system operation
   Allow system to run for 5 minutes. Verify compressor cycles properly. Check that center vents blow cold air at 40-50°F (use thermometer inserted into vent). Inspect all AC line connections for frost buildup indicating leaks or restrictions. Low-side line should be cold to touch, high-side line should be warm.
9. 9

   Disconnect equipment and secure ports
   Turn off engine. Close all manifold valves. Carefully disconnect gauge hoses from service ports starting with low-side, then high-side. Some refrigerant will escape - this is normal. Install service port caps immediately to prevent contamination and moisture entry.

Reassembly

1. Ensure both service port caps are installed securely
2. Wipe down any oil residue from service port area
3. Store all AC service equipment properly and ensure refrigerant containers are sealed

Verification

• Start engine and run AC system on MAX COLD for 10 minutes
• Verify vent temperature reaches 40-50°F using thermometer
• Confirm compressor clutch engages and disengages normally
• Check that low-side pressure is 25-35 psi and high-side is 200-250 psi with system running at idle and ambient temperature 75-85°F
• Listen for any unusual noises from compressor indicating overcharge or other issues
• Inspect all visible AC lines and connections for any signs of oil leaks or frost buildup over next few days of operation

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