Leaking Or Damaged Components, Replacing, Empty Refrigerant Circuit Except A/C Compressor And Receiver/Dryer: Notes

WARNING: This page is about a different car, the 2025 Audi S3, 2025 Audi RS 3, and 2025 Audi A3 Quattro. However, it is still accessible from the selected car via links, so may be relevant.

If there is only a small leakage (micro leakage) and the refrigerant is leaking over a long time period, but very slowly, then moisture penetration is unlikely and thus can be neglected. The refrigerant circuit does not need to be cleaned in this case. Refer to LEAKING OR DAMAGED COMPONENTS, REPLACING, FILLED REFRIGERANT CIRCUIT EXCEPT A/C COMPRESSOR AND RECEIVER/DRYER .
If the leakage is larger and refrigerant oil leaked out, then the moisture penetration into the refrigerant circuit is high. In this case the refrigerant circuit must be cleaned.
If there is a large leakage through which an unknown amount of refrigerant oil leaked out, then the refrigerant circuit must be cleaned.
If the refrigerant circuit was open for a longer period of time and moisture was able to penetrate, then the refrigerant circuit must be cleaned.

Procedure

The refrigerant circuit is completely empty (for example with larger leaks or cracked hose line)

Procedure

-- Remove the faulty component. Refer to Refrigerant Circuit .

-- Refer to REFRIGERANT CIRCUIT, CLEANING .

Electrically-Driven A/C Compressor

-- Drain all refrigerant oil from the A/C compressor, for this, clean the A/C compressor. Refer to MAIN WIRING DIAGRAM, ELECTRICALLY-DRIVEN A/C COMPRESSOR, CLEANING .

-- Fill the entire amount of refrigerant oil (unused refrigerant oil) intended for the refrigerant circuit via the high and low pressure connection of the A/C compressor. Refer to APPROVED REFRIGERANT OILS AND REFRIGERANT OIL CAPACITIES .

Mechanically Driven A/C Compressor

-- Remove the A/C compressor. Refer to A/C COMPRESSOR, REMOVING AND INSTALLING .

-- Remove the oil drain plug -2-.

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Tip

The design of the oil drain plug -2- and the seal -3- is different, depending on the manufacturer. Refer to A/C Compressor .
Pay attention to the tightening specifications of the oil drain plug -2-.
Refer to OVERVIEW - A/C COMPRESSOR .
If the tightening specification for the oil drain plug is not given in the overview - A/C compressor: "Denso" : 30 Nm
If the tightening specification for the oil drain plug is not given in the overview - A/C compressor: "Delphi" : 15 Nm
If the tightening specification for the oil drain plug is not given in the overview - A/C compressor: "Sanden" / "Zexel- / Valeo-" : 10 Nm
If the oil drain plug seal is not available as a replacement part, then the removed seals may be reused, as an exception. Check for damage before installing.
After charging the refrigerant circuit, check the installed oil drain plug for leaks. Refer to LEAKS, DETERMINING USING ELECTRONIC LEAK DETECTOR .

-- Pour out the used refrigerant oil from the A/C compressor. For best results when draining the A/C compressor, turn the belt pulley or A/C clutch plate during the process.

-- Fill the entire amount of refrigerant oil (unused refrigerant oil) intended for the refrigerant circuit via the oil drain plug opening of the A/C compressor. Refer to APPROVED REFRIGERANT OILS AND REFRIGERANT OIL CAPACITIES .

Continuation for all vehicles

-- Replace the receiver/dryer. Refer to Refrigerant Circuit .

-- Assemble the refrigerant circuit.

-- Charge the refrigerant circuit. Refer to REFRIGERANT CIRCUIT, CHARGING .