64 52 521 Replacing A/C System Compressor (N52K)

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WARNING:

Risk of injury!

Refrigerant circuit is under high pressure!

Work on the cooling system may only be carried out when it has cooled down.

Follow safety instructions for handling R134a refrigerant . See 64 50... Instructions For Handling Refrigerant R134a and/or 64 50... Safety Instructions For Handling Refrigerant R134A .

Follow safety instructions for handling refrigerant oil . Refer to 64 50... Instructions For Handling Refrigerant Oil (For Refrigerant R134a) .

Avoid contact with refrigerant and refrigerant oil.

IMPORTANT:

Aluminum-magnesium materials.

No steel screws/bolts may be used due to the threat of electrochemical corrosion.

A magnesium crankcase requires aluminum screws/bolts exclusively.

Aluminum screws/bolts must be replaced each time they are released.

The end faces of aluminum 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 . See 64 52... Instructions For Compressor Replacement .

Follow instructions for opening and replacing parts in refrigerant circuit. Refer to 64 52... Instructions For Opening And Replacing Parts In Refrigerant Circuit .

If A/C system is opened for more than 24 hours:

Replacing desiccant insert for A/C system . Refer to 64 53 515 Replacing Desiccant Insert For A/C System .

Necessary preliminary tasks:

Drawing off, evacuating and filling the A/C system are not included in the time value given for this work operation. Refer to 64 50 009 Drawing Off, Evacuating And Filling A/C System (R134A)
Release expansion tank and place to one side
Remove alternator drive belt . Refer to 11 28 010 REPLACING ALTERNATOR DRIVE BELT (N52K) .
Remove coolant thermostat . See THERMOSTAT AND CONNECTOR .

Release screws (1) and disconnect plug connection on compressor.

Disconnect pressure and suction lines.

Installation:

Replace all sealing rings and moisten with refrigerant oil.

Tightening torque, see 64 52 1AZ in 64 52 A/C COMPRESSOR .

Fig 1: Identifying Screws

Courtesy of BMW OF NORTH AMERICA, INC.

NOTE: Secure compressor (3) against falling out.

Release screw (1).

Release screws (2).

Tightening torque, see 64 52 3AZ in 64 52 A/C COMPRESSOR .

Remove compressor towards front.

Fig 2: Identifying Compressor & Screws

Courtesy of BMW OF NORTH AMERICA, INC.

After installation:

Evacuate and fill A/C system . Refer to 64 50 009 Drawing Off, Evacuating And Filling A/C System (R134A) .
Fill cooling system , vent and check for leaks. Refer to 17 00 039 VENTING COOLING SYSTEM AND CHECKING FOR WATER LEAKS (N52/N52K/N51/N53) .
Assemble engine