This procedure evacuates the old refrigerant from the AC system, checks for leaks, and recharges with the correct amount of R-134a refrigerant and PAG oil for the 2016-2024 Hyundai Tucson 2.5L I4 AWD.

Warnings

Tools required

Parts

• R-134a refrigerant × 1 — 17-21 oz total capacity
• PAG 46 compressor oil × 1 — Use OEM specification
• AC service port caps × 2 — Replace if damaged

Preparation

1. Verify that AC system requires recharge by checking low-side pressure with engine off (should be 60-90 psi when fully charged at 70°F ambient)
2. Locate the low-pressure service port (larger port with black or blue cap) on the suction line near the accumulator
3. Locate the high-pressure service port (smaller port with red cap) on the liquid line near the condenser
4. Ensure ambient temperature is above 50°F for accurate charging
5. Have recovery machine, vacuum pump, and refrigerant ready

Procedure

1. 1

   Recover existing refrigerant
   Connect the AC recovery machine to both the low-pressure and high-pressure service ports. Follow the recovery machine manufacturer's instructions to safely remove all remaining refrigerant from the system. Record the amount of refrigerant and oil recovered for comparison.
2. 2

   Inspect system for leaks
   With the system empty, visually inspect all AC line fittings, the compressor, condenser, and evaporator connections for signs of oil residue or damage. If a leak is suspected, use an electronic leak detector or pressurize the system with nitrogen and soap solution to locate the leak. Repair any leaks before proceeding.
3. 3

   Evacuate the system
   Connect a vacuum pump to the manifold gauge set. Open both low and high side valves and run the vacuum pump for a minimum of 30 minutes to remove all moisture and air from the system. The system should reach and hold at least 29 inches of mercury (Hg) vacuum. After 30 minutes, close the valves and turn off the pump. Monitor the gauge for 10 minutes - vacuum should hold steady. If vacuum drops, there is a leak that must be repaired.
4. 4

   Add PAG oil if necessary
   Calculate the amount of PAG 46 oil to add based on what was recovered. If less than 3 oz was recovered, add the difference to bring the total system oil to approximately 5-6 oz. Add oil through the low-pressure port using an oil injector tool. If the compressor was replaced or significant oil was lost, refer to component replacement procedures for specific oil quantities.
5. 5

   Connect recharge equipment
   Connect the manifold gauge set or recharge machine to the low-pressure service port (engine off). Ensure all connections are secure. Do not connect to the high-pressure port during charging unless using a full recovery/recharge machine.
6. 6

   Begin refrigerant charge
   Start the engine and set the AC controls to MAX cooling, recirculation mode, and highest blower speed. Open the low-pressure valve on the manifold gauge set and begin adding R-134a refrigerant. The 2016-2024 Tucson 2.5L AWD requires 17-21 oz (approximately 480-595 grams) of R-134a. Add refrigerant slowly while monitoring the low-side gauge.
7. 7

   Monitor system pressures
   With the engine running at 1500-2000 RPM and AC on MAX, monitor both gauges. Target pressures at 70-80°F ambient temperature: Low side should be 25-35 psi, high side should be 200-250 psi. At 90-100°F ambient: Low side 35-45 psi, high side 275-325 psi. Adjust refrigerant charge until pressures are within specification.
8. 8

   Verify compressor operation
   Observe that the AC compressor clutch engages and remains engaged without cycling excessively. Listen for unusual noises from the compressor. Check that the compressor discharge line (high side) is hot to the touch and the suction line (low side) is cold and may have condensation.
9. 9

   Check vent temperature
   Insert a thermometer into the center dashboard vent. With ambient temperature of 70-80°F, vent temperature should reach 38-45°F within 5-10 minutes. If vent temperature is not cold enough, verify refrigerant charge and check for airflow restrictions or blend door issues.
10. 10

    Finalize and disconnect
    Once the correct charge is achieved and system is operating properly, close all valves on the manifold gauge set. Turn off the engine and AC. Disconnect the gauges from the service ports quickly to minimize refrigerant loss. Replace the service port caps securely to prevent contamination and slow leaks.

Reassembly

1. No reassembly required for standard AC recharge procedure
2. If any AC line fittings were disconnected during repair, install new O-rings lubricated with PAG oil and torque to 20.0 Nm (15.0 lb-ft) per the AC line fittings specification

Verification

• Start the engine and turn AC to MAX cooling with recirculation on
• Verify center vent temperature reaches 38-45°F at 70-80°F ambient temperature within 5-10 minutes
• Confirm AC compressor clutch engages smoothly without excessive cycling (should cycle off only when very cold or at idle)
• Check that low-side pressure is 25-45 psi and high-side pressure is 200-325 psi depending on ambient temperature
• Listen for any unusual noises from the compressor or AC system components
• Verify no refrigerant odor or visible oil leaks around service ports and fittings
• Test AC performance over several drive cycles to ensure consistent cooling

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