64 52 ... Instructions for compressor replacement

Important! 

Compressors with plastic belt pulleys:

• Avoid impacts/knocks to plastic belt pulley (caused by tools, contact with base).
• Return faulty compressors in their original packaging only.

Important! 

When starting up a new compressor for the first time, it is absolutely essential to carry out the following breaking-in procedure:

• Switch on A/C system
• Set all air vents in instrument cluster to "OPEN"
• Start engine and let it stabilize at idle speed
• Set blower output to min. 75% of max. blower output
• Switch on A/C system and run for at least 2 minutes at idle speed (risk of damage at higher speed!)

When evacuating the air-conditioning system, refrigerant oil is also extracted and collected in the oil separator of the service station.

Fig 1: Identifying A/C System Evacuating

Courtesy of BMW OF NORTH AMERICA, INC.

After evacuation, the refrigerant must be filtered in the service station as the oil separator could still contain a liquid refrigerant/oil mixture. The filtering process gasifies the refrigerant completely and only the previously bound refrigerant oil remains in the oil separator. Measure and note down this quantity of refrigerant oil. Refer to 64 50 009 Drawing off, evacuating and filling A/C system (R 134a) .

Transfer the refrigerant oil remaining in the previous compressor via the filler plug completely into a measuring container.

Fig 2: Transferring Refrigerant Oil

Courtesy of BMW OF NORTH AMERICA, INC.

Measure the amount of refrigerant oil collected from the previous compressor.

Fig 3: Measuring Refrigerant Oil Collected

Courtesy of BMW OF NORTH AMERICA, INC.

Depending on its design, the new compressor is filled at the factory with 120 to 200 g refrigerant oil. Open filler plug and pour entire contents of compressor into a clean container.

Fig 4: Pouring Oil Into Clean Container

Courtesy of BMW OF NORTH AMERICA, INC.

Installation: 

If necessary, replace gasket.

Observe tightening torque, 64 52 2AZ. Refer to HEATING AND AIR CONDITIONING - TIGHTENING TORQUES .

From this refrigerant oil, pour the same amount (as drained from the previous compressor) + 10 g extra into a clean measuring container and pour again into the new compressor.

Fig 5: Pouring Refrigerant Oil

Courtesy of BMW OF NORTH AMERICA, INC.

Remaining refrigerant oil can be poured into service station tank, refer to 64 50 009 Drawing off, evacuating and filling A/C system (R 134a) .

Otherwise the excess refrigerant oil must be disposed of correctly.

On account of its hygroscopic properties, refrigerant oil must not be stored in open containers.

The refrigerant oil drawn off from the oil separator of the service station and from the previous compressor must not be reused and must be correctly disposed of.

Fig 6: Disposing Of Used Refrigerant Oil

Courtesy of BMW OF NORTH AMERICA, INC.

After installing the new compressor, it is essential before filling the A/C system to pour the same amount of the previously drawn off refrigerant oil into the system again, refer to 64 50 009 Drawing off, evacuating and filling A/C system (R 134a) .

Fig 7: Pouring Refrigerant Oil In A/C System

Courtesy of BMW OF NORTH AMERICA, INC.

Installation: 

If A/C system is opened for more than 24 hours: Replace drier bottle/drier insert. Refer to 64 53 510 Removing and installing / replacing drier flask for air conditioner .