After Installing A/C Compressor

After Installing A/C Compressor

• The A/C compressor is continuously driven by the engine (no A/C clutch).

• Should a compressor malfunction (lock-up) the overload protection for the compressor shaft is triggered. An indication the compressor has locked-up is deformations/bumps on the ribbed belt pulley, but these are not always easy to detect. Another indicator is abraded rubber material in the area of the ribbed belt pulley/overload protection.

• The compressor has an internal oil circuit to ensure the compressor is not damaged should the refrigerant circuit be empty. Prerequisite for the internal lubrication is residual refrigerant oil in compressor. Approximately 40 to 50 cm3 of refrigerant oil remains in the A/C compressor.

• The engine should only be started when the refrigerant circuit is completely and properly installed. 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.

• If it is necessary to start the engine with a discharged refrigerant circuit:

• Refrigerant circuit must be fully assembled.

• At least 1/4 of the prescribed refrigerant oil must be in the A/C compressor.

• Engine speed should not increase above 2500 RPM.

• Engine should only run as long as absolutely necessary

CAUTION!
Do not start engine with open refrigerant system (E.g.: refrigerant lines not connected to compressor or other refrigerant system components). Compressor will overheat and will be damaged.

- Only start engine after refrigerant circuit has been assembled.

- After installing a new A/C compressor or fresh refrigerant oil has been filled into compressor (e.g. after blowing through the A/C system), turn ribbed belt pulley of A/C compressor 10 rotations by hand before starting the engine. This prevents damage to the A/C compressor

- If possible start engine only with a filled refrigerant circuit.

• Note the following when starting engine for first time after filling refrigerant circuit:

- Start engine with A/C compressor switched off ("ECON" mode) and wait until the idling speed stabilizes.

- Open an instrument cluster air vent.

- Select temperature preset "Lo" on A/C Control Head (E87).

- Now switch A/C compressor on ("Auto" mode) and allow engine to run for 5 minutes at idling speed.