Instructions for AC Compressor Replacement Procedure

1. Preparation procedures

• Identify the cause of failure of the old AC compressor – if the issue is not resolved, the new installed AC compressor risks failing as well.

• Make sure the A/C system is clean – if chemical flushing is used, all cleaning agents must be removed from the system.

• Do not add additives (sealants or maintenance solutions) to the A/C system.

• Use new gaskets and only specific oil for gasket lubrication.

• Keep the system closed. The compressor oil has a strong hygroscopic effect, which is why the system must remain closed as much as possible, and oil should only be added shortly before closing the refrigerant circuit.

2. System lubrication

• Oil distribution in the system:
+ Compressor 50%
+ Evaporator 20%
+ Condenser 10%
+ Dryer 10%
+ Pipes 10%

• Balancing the system oil – Please note that approximately 50% of the oil is distributed to the other system components. Measure the oil quantity in the old compressor and adjust the amount in the new compressor. Use the correct type and quantity of oil for each circuit type.

• Too much oil will increase the load on the piston/gear system, which may lead to blockage.

• Too little oil will cause insufficient compressor lubrication, increased component temperature, and oil burning on the compressor suction side.

• If the system has been flushed, take into account that the entire system is left without oil.

DO NOT USE UNIVERSAL OILS!

3. Installation

• Before installation, rotate the compressor shaft several times (10–15) so the oil is distributed inside, then keep it for about 3 minutes in a position that facilitates oil penetration to the shaft seal on the clutch side.

• Always follow the tightening torques.

• Replace the dryer at every intervention in the system.

• System connections must be closed immediately or sealed with caps or plugs. Otherwise, air humidity will enter the system.

• Since the same compressor can be used for different vehicles or systems, the oil filling quantity and viscosity must be checked and/or corrected according to the manufacturer/model specifications before installing the compressor.

4. Charging the system with refrigerant

• Vacuum time must be respected according to the repair manual. The efficiency of the cooling system depends on this detail.

• After depressurization and ensuring the system is sealed, fill the installation properly with oil and refrigerant, according to specific documentation.

5. Final checks

• Start the engine

• Turn on the air conditioning and set the temperature to minimum. Keep it running for at least 5 minutes.

• DO NOT increase engine speed during this time!

• After 5 minutes all compressor oil, initially stored in it, is transported through the system. Now it is possible to increase engine speed and test the efficiency of the AC system.

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