A/C COMPRESSOR
Note. Depending on time period of production and on engine, compressor construction type may vary. At the start of production, Denso (type 7 SEU 16 or 7 SEU 17) A/C compressors were installed; beginning with MY 2004 A/C compressors made by other manufacturers (Delphi, Sanden or Zexel Valeo) were installed, Refer to Removal and Installation . These A/C compressors are available as replacement parts with different oil fill capacities, therefore note capacity on A/C compressor and the exact part number. Refer to REFRIGERANT R134A CAPACITIES . Beginning the production year 2006, the name of the Zexel A/C compressor was changed from Zexel to Valeo. Depending on A/C compressor type, different refrigerant oil fill capacities are designated for the refrigerant circuit. The reason for the different oil capacities in the A/C compressor for an otherwise identical refrigerant circuit lies in the design of the A/C compressor itself, note these oil capacities. Too much oil in the circuit leads to high pressures and to a reduction in the system cooling performance, too little oil may lead to lubrication problems in the A/C compressor, refer to REFRIGERANT R134A CAPACITIES . If a new compressor has been installed or new refrigerant oil has been put into the A/C compressor (e.g. after blowing through the A/C system), the A/C compressor must be turned by hand approximately 10 revolutions. This ensures that the compressor is not damaged when activated.
Removing
Evacuate the refrigerant circuit. Refer to EVACUATING REFRIGERANT CIRCUIT .
Disconnect refrigerant lines from A/C compressor, refer to REFRIGERANT LINES, DISCONNECTING FROM A/C COMPRESSOR .
Remove A/C compressor from bracket. Refer to COMPRESSOR, REMOVING FROM BRACKET .
Installing
Installation is carried out in the reverse order, when doing this note the following
Before installing the A/C compressor, refer to Removal and Installation .
Note. Coat the O-ring with refrigerant oil before installing. Refer to REFRIGERANT CIRCUIT O-RINGS . An uncertain quantity of refrigerant oil remains in a removed A/C compressor, therefore observe notes for replacing the A/C compressor. Refer to COMPRESSOR, REPLACING WITHOUT FLUSHING REFRIGERANT CIRCUIT .
- Tightening specifications, refer to «COMPRESSOR, REMOVING FROM BRACKET»(/audi/a3/8p-2-2008-2013/remont/automatic-hvac-system/#air-conditioning__compressor-removing-from-bracket) and «REFRIGERANT LINES, DISCONNECTING FROM A/C COMPRESSOR»(/audi/a3/8p-2-2008-2013/remont/automatic-hvac-system/#air-conditioning__refrigerant-lines-disconnecting-from-ac-compressor) .
- Replace the O-rings at the opened connection locations. Refer to «REFRIGERANT CIRCUIT O-RINGS»(/audi/a3/8p-2-2008-2013/remont/automatic-hvac-system/#air-conditioning__refrigerant-circuit-o-rings) .
Only start engine after refrigerant circuit has been assembled.
If a new A/C compressor has been installed or fresh refrigerant oil has been filled into the A/C compressor before installing ribbed belt (for example, after cleaning refrigerant circuit), the A/C compressor must be turned by hand approximately 10 turns. This ensures that the A/C compressor will not be damaged when engine is first started.
If possible start engine only with a filled refrigerant circuit.
Note. Different A/C compressors, depending on production time period and on engine, refer to REFRIGERANT CIRCUIT, SERVICING . The A/C compressor is always driven by a belt pulley (there is no magnetic clutch). The compressor has an internal oil circuit to ensure the A/C compressor is not damaged when refrigerant circuit is empty. Prerequisite for the internal lubrication is residual refrigerant oil in A/C compressor. The engine may only be started when the refrigerant circuit is installed correctly. For example; if the refrigerant lines are not connected to A/C compressor, when the engine is running the A/C compressor may heat up (via internal heat generation) so much that the A/C compressor will be damaged. A/C Compressor Regulator Valve -N280- is not activated when the refrigerant circuit is empty and the A/C compressor idles with the engine. As there is no refrigerant in the circuit the oil required to lubricate is not fed to the A/C compressor. To prevent damage, the A/C compressor is lubricated by an internal oil circuit.
- If it is necessary to start the engine with a discharged refrigerant circuit. Refer to «A/C SYSTEM, OPERATING AFTER FILLING REFRIGERANT CIRCUIT»(/audi/a3/8p-2-2008-2013/remont/automatic-hvac-system/#air-conditioning__ac-system-operating-after-filling-refrigerant) .