A/C Compressor

A/C Compressor

• Mark connector to A/C Compressor Regulator Valve (N280) due to risk of interchange with connector to electric engine mount if connectors are interchanged, no DTC is entered in DTC memory, however the evaporator may ice-up since the compressor is actuated continuously.

• Compressor as replacement part has different oil fill capacities, therefore note the exact part number. The reason for the different oil capacities in the compressor lies in the design of the compressor itself, note these oil 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.

• Different refrigerant oil capacities are designated depending on the compressor type "6 SEU 14", "7 SEU 16" or " 7 SEU 17".

Removing

- Drain the refrigerant circuit.

- Remove compressor from bracket not for vehicles with 8 cylinder diesel engine. Refer to=> [ Compressor, Removing from Bracket, 6 Cylinder, 8 Cylinder MPI and 8 Cylinder Diesel ] Service and Repair.

- On vehicles with 12 cylinder engine, perform the preparatory work described. Refer to => [ Compressor from Bracket, 12 Cylinder ] Service and Repair

- Disconnect refrigerant lines from compressor. Refer to => [ Refrigerant Lines, Disconnecting and Connecting from Compressor ] Removal and Replacement.

- Remove compressor from bracket on vehicles with 8 cylinder diesel engine. Refer to=> [ Compressor, Removing from Bracket, 6 Cylinder, 8 Cylinder MPI and 8 Cylinder Diesel ] Service and Repair.

Installing

Installation is carried out in the reverse order, when doing this note the following:

Before installing compressor: review Refrigerant Servicing.

• Tightening torques, refer to => [ Compressor, Removing from Bracket, 6 Cylinder, 8 Cylinder MPI and 8 Cylinder Diesel ] Service and Repair and => [ Refrigerant Lines, Disconnecting and Connecting from Compressor ] Removal and Replacement.

• Replace the O-ring seals on opened connection points.

- Start engine first after reconnecting refrigerant circuit.

- If a new compressor has been installed or fresh refrigerant oil has been added to the compressor before installing the ribbed belt after flushing the refrigerant circuit), rotate the compressor approximately 10 rotations by hand to prevent it from being damaged when the engine is started.

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

• Different compressors are used depending on the country, production date and the engine. Refer to => [ A/C Compressor ] Service and Repair.

• Coat O-ring seals lightly with refrigerant oil before installing. Refer to => [ Refrigerant Circuit O-Ring Seals ] Refrigerant Circuit O-Ring Seals.

• The compressor is always driven by a pulley/the drive unit. There is no magnetic clutch.

• 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.

• An uncertain quantity of refrigerant oil remains in a removed compressor, therefore observe notes for replacing the compressor.

• 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. To prevent damage to the compressor the compressor is lubricated by an "internal oil circuit".

If the engine must be started when the refrigerant circuit is empty, perform the following steps to prevent compressor damage. Refer to=> [ Operating A/C System after Filling Refrigerant Circuit ] Operating A/C System after Filling Refrigerant Circuit.

- Evacuate and fill the refrigerant circuit.

- Operate the A/C system after filling the refrigerant circuit. Refer to=> [ Operating A/C System after Filling Refrigerant Circuit ] Operating A/C System after Filling Refrigerant Circuit

• Note the information regarding operating the A/C system after filling.