Capacities For AUDI A8 (4H_) From 2010 And AUDI A8 Hybrid (4H_) From 2012
Features Of The Refrigerant System:
- Expansion Valve
- Depending on the vehicle equipment level with one or two evaporators
- Refrigerant line with inner heat exchanger.
- Dryer cartridge in receiver/dryer on condenser
- Mechanically driven "Denso" A/C compressor with A/C Compressor Regulator Valve -N280-. Refer to SYSTEM OVERVIEW - REFRIGERANT CIRCUIT / SYSTEM OVERVIEW - REFRIGERANT CIRCUIT (vehicle-specific repair information) and the parts information (all vehicles except A8 Hybrid).
- For vehicles with a high voltage system (Audi A8 Hybrid) with electrically-driven "Denso" A/C compressors. Refer to SYSTEM OVERVIEW - REFRIGERANT CIRCUIT / SYSTEM OVERVIEW - REFRIGERANT CIRCUIT (vehicle-specific repair information) and the parts information.
Capacities may vary for the refrigerant and the refrigerant oil on vehicles with an 8-cylinder TDI engine.
- Due to the installed location of the A/C compressor (above the engine), the refrigerant oil capacity may vary from what is on the A/C compressor data plate on vehicles with an 8-cylinder TDI engine.
| Vehicle model | Production period | Total quantity of oil in refrigerant circuit in cm(1) | Quantity of refrigerant oil in replacement compressor in cm(1) | Differing features of this refrigerant circuit | ||
|---|---|---|---|---|---|---|
| Audi A8 (all vehicles except for the 8-cylinder TDI engine) | From 03/2010 | |||||
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130+ /- 10 |
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130+ /- 10 |
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| Audi A8 (8-cylinder TDI engine only) | ||||||
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180+ /- 10 |
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180+ /- 10 |
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| Audi A8 Hybrid | From 01/2012 | 160+ /- 20 | 160+ /- 20 |
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On vehicles with an 8-cylinder TDI engine, the refrigerant oil quantity was increased from 130 ccm to 180 ccm in the refrigerant circuit from the vehicle identification number 4H_ BN 018846. To compensate, the refrigerant quantity must be slightly reduced. Since the filling capacity information on the information label does not change, proceed as follows: On vehicles that were built up to the specified vehicle identification number, check whether the refrigerant oil capacity was already topped up during a previous workshop visit. If not, fill the refrigerant circuit with an additional 50 ccm of refrigerant oil. Then amend the fill capacity for the refrigerant in the information label with a waterproof marker accordingly and fill the refrigerant circuit with the stated refrigerant quantity. Finally, document the performed changes in the vehicle data. For vehicles built from the specified vehicle identification number, check the refrigerant capacity specification on the information label and if necessary, amend the quantities with a waterproof marker accordingly and then fill the refrigerant circuit with the specified refrigerant quantity.
The same refrigerant oil quantity was added during production for other engines as for vehicles with an 8-cylinder TDI engine up to the vehicle identification number 4H_ BN 018845. Vehicles with an 8-cylinder TDI engine starting from the VIN 4H_ 018846 are filled with a larger amount of refrigerant oil during production. This refrigerant oil quantity applies retroactively to all vehicles with an 8-cylinder TDI engine. If the refrigerant circuit is refilled or the A/C compressor is replaced after cleaning the refrigerant circuit, for example, on vehicles with an 8 cylinder TDI engine, check the refrigerant oil quantity in the refrigerant circuit (for example, in open lines or component connections, or via the A/C service station before filling with refrigerant) and refill it with the correct quantity if necessary. If the A/C compressor is replaced without needing to clean the refrigerant circuit, adjust the refrigerant oil quantity in the newly installed A/C compressor so that it corresponds with the quantity of oil that was poured out of the old A/C compressor (and if necessary fill for corresponding vehicles through the specified VIN above). Refer to REFRIGERANT CIRCUIT COMPONENTS, REPLACING .
The reason for the different oil capacities inside the A/C compressor is due to the design of the A/C compressor (with or with an oil separator on the high pressure connection) or to the design of the refrigerant circuit if the A/C compressors are have the identical design. Pay attention to the different capacities. Too much oil in the circuit leads to higher pressures and reduces cooling performance of the system. Too little oil may lead to lubrication problems in the compressor.
These A/C compressors are available as replacement parts with different oil fill capacities, therefore pay attention to the exact part number. Refer to the parts information.
Too much oil in the circuit leads to higher pressures and reduces cooling performance of the A/C system. Too little oil may lead to lubrication problems in the compressor, therefore note the specified refrigerant oil quantities.
A data plate may be attached to the A/C compressor by the manufacturer, indicating the part number and refrigerant oil quantity.
For all vehicles except for the Audi A8 Hybrid, the mechanically driven A/C compressors manufactured by "Denso" are installed at the start of production. Compressors from other manufacturers may also be installed at a later time. Refer to SYSTEM OVERVIEW - REFRIGERANT CIRCUIT / SYSTEM OVERVIEW - REFRIGERANT CIRCUIT (vehicle-specific repair information).
An electrically driven A/C compressor manufactured by "Denso" (Electrical A/C Compressor -V470- with A/C Compressor Control Module -J842-) is installed at the start of production for the Audi A8 Hybrid. There is no A/C Compressor Regulator Valve -N280- present in this A/C compressor.
A/C compressors with a refrigerant oil quantity of 200 ccm were installed at the start of production on Audi A8 Hybrid vehicles. Shortly after the start of production, the refrigerant oil quantity was reduced to 160 ccm. Do not reduce the refrigerant oil quantity on a vehicle in which an A/C compressor with a refrigerant oil capacity of 200 ccm is installed. If, for example, the refrigerant circuit is flushed, a total quantity of 160 ccm of refrigerant is also to be filled in the refrigerant circuit for this vehicle. The replacement A/C compressor already contains the correct amount of refrigerant oil. Refer to the parts information.