A/C System, Operating after Filling Refrigerant Circuit

A/C System, Operating after Filling Refrigerant Circuit

• Only start engine after refrigerant circuit has been assembled.

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

• Do not start the engine while evacuating the refrigerant circuit or when the circuit is already evacuated (the compressor could be damaged) => Refrigerant R134a - Servicing.

• Compressor is always driven by the pulley or by the driveshaft (there is no magnetic clutch). To prevent damage when the compressor is idling, it is lubricated by an "internal oil circuit".

• The compressor has an "internal oil circuit" to ensure the compressor is not damaged when refrigerant circuit is empty. Prerequisite for the internal lubrication is residual refrigerant oil in compressor.

• The engine may only be started when the refrigerant circuit is installed correctly. If for example the refrigerant lines are not connected to the compressor and the engine is started then the compressor may be destroyed by the build-up of internal heat.

• A/C Compressor Regulator Valve (N280) is not activated when the refrigerant circuit is empty and the compressor idles with the engine. As there is no refrigerant in the circuit the oil required to lubricate is not fed to the compressor.

• All removed parts are re-installed.

• The refrigerant circuit is filled => Refrigerant R134a - Servicing.

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

• Refrigerant circuit must fully assembled.

• There must be no vacuum in the refrigerant circuit.

• At least 1/4 of the specified refrigerant oil must be in the compressor.

• No not rev engine higher than 2500 rpm.

• The engine should only run as long as absolutely necessary.

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

- Start engine with compressor switched off ("Econ" operating mode set, indicator light in AC button does not light up) and wait until engine idle speed has stabilized.

- Open all instrument panel vents.

- Set the temperature preset on the A/C Control Head Climatronic Control Module (J255) to "cold" (for the driver and passenger side).

- Switch the compressor on by press the AC button ("Auto" is selected and indicator light in the AC button is lit) and let the compressor run for at least 5 minutes with the engine in idle.

• Note the information regarding operating the A/C system after filling => Air Conditioning with R134a refrigerant.