Audi A4: Receiver/Dryer or Accumulator and Restrictor, Replacing after Cleaning Refrigerant Circuit

  Note

Cleaning the refrigerant circuit means flushing it with refrigerant R134a. Refer to → Chapter "Refrigerant Circuit, Cleaning (Flushing), with Refrigerant R134a" or blowing through with compressed air and nitrogen. Refer to → Chapter "Refrigerant Circuit, Flushing with Compressed Air and Nitrogen").

For example, on account of ingress of moisture (refrigerant circuit open for lengthy period) or contamination

- Discharge the refrigerant circuit.

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

- Rectify cause of trouble.

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

- Examine expansion valve for dirt or corrosion; replace if necessary.

Electrically-Driven A/C Compressor

- Flush the old refrigerant oil out of A/C compressor → Chapter "Electrically Driven A/C Compressor, Rinsing (Remove Refrigerant Oil)".

Mechanically Driven A/C Compressor

- Remove oil drain plug from A/C compressor.

  Note

There are different versions of the oil drain plug and its seal (it can be either an O-ring or a gasket; replace). Refer to → Chapter "Leaking or Damaged Components except A/C Compressor, Reservoir or Receiver/Dryer" and 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.

- Pour old refrigerant oil out of A/C compressor.

  Note

Dispose of the old refrigerant oil. Pay attention to local regulations).

All A/C Compressors

- Then add to the compressor the new refrigerant oil quantity which matches the refrigerant oil quantity in the replacement compressor (or the specified refrigerant oil quantity in vehicles with two evaporators if necessary) → Chapter "Approved Refrigerant Oils and Capacities".

  Note

• 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 "Refrigerant R134a Capacities, Refrigerant Oil and Approved Refrigerant Oils".
• If dirt has penetrated into the compressor with the refrigerant circuit open (e.g. after an accident), compressor is to be replaced.
• In vehicles with two evaporators, the refrigerant oil quantity in refrigerant circuit may be greater than the quantity which is found in the replacement compressor, if necessary add the remaining refrigerant oil quantity to the refrigerant circuit. Refer to → Chapter "Refrigerant Circuit, Flushing with Compressed Air and Nitrogen".

All Vehicles

- Replace 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 charge the refrigerant circuit.

Receiver/dryer or Accumulator, Replacing without the Need for Flushing Refrigerant Circuit

  Note

Cleaning the refrigerant circuit means flushing it with refrigerant R134a. Refer to → Chapter "Refrigerant Circuit, Cleaning (Flushing), with Refrigerant R134a" or blowing through with compressed air and nitrogen. Refer to → Chapter "Refrigerant Circuit, Flushing with Compressed Air and Nitrogen").

For example, in the event of accident damage; no escape of refrigerant and no ingress of moisture and dirt into circuit.

- Discharge the refrigerant circuit.

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

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

- Remove dirt from receiver or reservoir.

- Weigh removed receiver/dryer or reservoir.

- Add refrigerant oil to the reservoir until it is the same weight as the receiver/dryer that was removed.

- Install new receiver/dryer or reservoir.

- Assemble, evacuate and charge the refrigerant circuit.

Dryer Cartridge and Dryer Bag, Replacing without the Need for Flushing Refrigerant Circuit

  Note

Cleaning the refrigerant circuit means flushing it with refrigerant R134a. Refer to → Chapter "Refrigerant Circuit, Cleaning (Flushing), with Refrigerant R134a" or blowing through with compressed air and nitrogen. Refer to → Chapter "Refrigerant Circuit, Flushing with Compressed Air and Nitrogen".

For example, no escape of refrigerant and no ingress of moisture and dirt into circuit.

- Discharge the refrigerant circuit.

- Replace the dryer cartridge. 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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