Audi A4: Leaking or Damaged Components except A/C Compressor, Reservoir or Receiver/Dryer

The refrigerant circuit was completely empty (for example with larger leak or cracked hose)

  Note

• In the event of only a minor leak with slow escape of refrigerant (e.g. at a small leakage point), the amount of refrigerant oil lost and the amount of moisture penetrating is not sufficient to influence operation of the air conditioner.
• The operations marked * are only to be implemented in case of a major leak (e.g. following an accident).

Electrically-Driven A/C Compressor

- Remove the faulty component. Refer to → Heating, Ventilation and Air Conditioning; Rep. Gr.87; System Overview - Refrigerant Circuit (vehicle-specific repair manual).

- Remove the electrically driven A/C compressor and flush. Refer to → Chapter "Electrically Driven A/C Compressor, Rinsing (Remove Refrigerant Oil)" *.

- Clean the refrigerant circuit (flush with Refrigerant R134a). Refer to → Chapter "Refrigerant Circuit, Cleaning (Flushing), with Refrigerant R134a" *.

- Fill the A/C compressor or the refrigerant circuit with completely with refrigerant oil to the specified capacity.

Mechanically Driven A/C Compressor

- Remove the faulty component. Refer to → Heating, Ventilation and Air Conditioning; Rep. Gr.87; System Overview - Refrigerant Circuit (vehicle-specific repair manual).

- Remove the A/C compressor. Refer to → Heating, Ventilation and Air Conditioning; Rep. Gr.87; A/C Compressor (vehicle-specific repair manual) *

- Remove the oil drain plug -B-/-D- from the A/C compressor -A- *

  Note

• There are different versions of the oil drain plug -B-/-D- and seal -C-/-E- (depending on the A/C compressor manufacturer).
• Pay close attention to the tightening specification for the oil drain plug -B-/-D- (depending on the A/C compressor manufacturer and the oil drain plug version). Refer to → Heating, Ventilation and Air Conditioning; Rep. Gr.87; A/C Compressor (vehicle-specific repair manual).
• A/C compressors made by "Denso" and "Nippondenso" have an oil drain plug -D-, for example, with a seal -E- installed on it; To replace. Refer to the Parts Catalog.
• A/C compressors made by "Sanden" or "Zexel" have an oil drain plug -B-, for example, with an O-ring -C- already installed. To replace. Refer to the Parts Catalog.
• To accelerate drainage of refrigerant oil, rotate the A/C compressor by way of clutch plate of A/C clutch, for example.
• Drain the old refrigerant oil from the A/C compressor.

All

  Note

• Then fill A/C compressor with quantity of fresh refrigerant oil corresponding to quantity of refrigerant oil in replacement A/C compressor. Refer to → Chapter "Approved Refrigerant Oils and Capacities" *
• Use different refrigerant oils and quantities for the various compressors. Refer to → Chapter "Approved Refrigerant Oils and Capacities".
• To ensure compressor lubrication on start-up, at least 40 cm³ of refrigerant oil must be poured into the compressor. The remainder can be added to the new reservoir or receiver/dryer. Refer to → Chapter "Approved Refrigerant Oils and Capacities".
• If dirt has penetrated into the compressor with the refrigerant circuit open (for example after an accident), compressor is to be replaced.
• Clean refrigerant circuit (flush with refrigerant R134a. Refer to → Chapter "Refrigerant Circuit, Cleaning (Flushing), with Refrigerant R134a" or blow through with compressed air and nitrogen. Refer to → Chapter "Refrigerant Circuit, Flushing with Compressed Air and Nitrogen" *.

- Replace dryer cartridge *, receiver/dryer * or accumulator * and restrictor. Refer to → Heating, Ventilation and Air Conditioning; Rep. Gr.87; System Overview - Refrigerant Circuit (vehicle-specific repair manual).

- Assemble, evacuate and recharge refrigerant circuit.

Leaking or Damaged Components except A/C Compressor, Reservoir or Receiver/Dryer

Refrigerant circuit still contains refrigerant (for example, with minor leak)

- Discharge the refrigerant circuit.

- Remove the malfunctioning component, flush with compressed air, collect escaping refrigerant oil.

- The new component is to be filled with the amount of refrigerant oil flushed out (positive 20 cm³ for evaporator, positive 10 cm³ for condenser, refrigerant lines and refrigerant hoses) as fresh refrigerant oil fill.

- Replace the restrictor. Refer to → Heating, Ventilation and Air Conditioning; Rep. Gr.87; System Overview - Refrigerant Circuit (vehicle-specific repair manual).

- Assemble, evacuate and charge the refrigerant circuit.

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