A/C Refrigerant System, Servicing Notes

A/C Refrigerant System, Servicing Notes

• No refrigerant must be added into the refrigerant circuit (discharge, evacuate and recharge refrigerant circuit).

• With the engine running the compressor is always driven, the compressor has no A/C clutch. For this reason, the engine should only be started when the refrigerant circuit is completely and properly installed. For example; if the refrigerant lines are not connected, when the engine is running the compressor may heat up (via internal heat generation) so much that the compressor will be damaged. The reason for internal heat generation is, the compressor operates with almost 0 % pump capacity against permanent resistance (locked circuit).

• To avoid compressor damage in the event the refrigerant circuit is empty, the compressor is designed is such way, the compressor is regulated to approx. 0 % capacity and is lubricated with the remaining oil in compressor via an internal oil circuit.

• A specific quantity of refrigerant oil is filled in a compressor as replacement part, this equates to the total quantity of refrigerant oil in the refrigerant circuit in vehicles with only one heating & A/C unit. On vehicles with two heating & A/C units (an additional rear heating & A/C unit), an additional quantity of refrigerant oil must be added to the refrigerant circuit.

• Zexel, Sanden and Denso compressors require different refrigerant oils.

• Coat O-ring seals lightly with refrigerant oil before installing.

• The specified diameters for O-rings seals and the tightening torques pertain also to the threaded connections of the refrigerant lines or refrigerant hoses between the separate components.

• Only install O-rings seals that are approved for Refrigerant R134a.

• Check pressures in refrigerant circuit.

• All other service and repair work on refrigerant circuit not covered in this Repair Information.