64 52 521 Replacing A/C Compressor

64 52 521 - Replacing A/C system compressor (N52, AWD)





Warning!
Risk of injury!
Refrigerant circuit is under high pressure!
Follow safety instructions for handling R 134a refrigerant.
Avoid contact with refrigerant and refrigerant oil.
Follow safety instructions for handling refrigerant oil 64 50 ... Instructions For Handling Refrigerant R 134a.





Important!
Aluminium-magnesium materials.
No steel screws/bolts may be used due to the threat of electrochemical corrosion.
A magnesium crankcase requires aluminium screws/bolts exclusively.
Aluminium screws/bolts must be replaced each time they are released.
The end faces of aluminium screws/bolts are painted blue for the purposes of reliable identification.
Jointing torque and angle of rotation must be observed without fail (risk of damage).





Important!
Risk of damage!
Restart engine only when A/C system has been correctly filled.
Read and comply with notes on replacing compressor 64 52 ... Instructions For Compressor Replacement.
Follow instructions Removal and Replacement for opening and replacing parts in refrigerant circuit!
If A/C system is opened for more than 24 hours:
Replacing drier insert for A/C system Service and Repair





Necessary preliminary tasks:
- Drawing off, evacuating and filling the A/C system 64 50 009 Drawing Off, Evacuating and Filling A/C System (R 134a) are not included in the time value given for this work operation
- Release expansion tank Service and Repair and place to one side
- Remove fan cowl Service and Repair
- Remove A/C compressor drive belt Service and Repair
- Remove front underbody protection Removing and Installing/Replacing Front Underbody Protection (AWD)
- Remove lower radiator cover
- Remove coolant thermostat Service and Repair





Release screws (1) and remove refrigerant lines.
Disconnect plug connection (2).

Installation Note:
Replace all sealing rings and moisten with refrigerant oil.
Tightening torque 64 52 1AZ [1][2]Compressor HVAC.





Release retaining clip (1) and feed out refrigerant line (2).





Release screw (1).
Tightening torque 64 52 3AZ [1][2]Compressor HVAC.





Secure compressor (2) against falling out.
Release bolts (1) and feed out compressor (2) towards bottom.
Tightening torque 64 52 3AZ [1][2]Compressor HVAC.





After installation:
- Evacuate and fill A/C system 64 50 009 Drawing Off, Evacuating and Filling A/C System (R 134a)
- Fill and vent cooling system 17 00 039 Venting Cooling System and Checking For Water Leaks and check for leaks