W12

A/C Compressor

Compressor driven by a ribbed belt

Removing

- Switch off the ignition.

- Drain the refrigerant circuit.

- Remove front noise insulation..

- Mark the direction of the operation of the ribbed belt - A -.

- Carefully remove the engine cover upward starting at rear and in the center - arrows 1 -.






- Then pull the engine cover forward off of the intake manifold - arrows 2 -.

- To relieve the tension on the ribbed belt, tilt the tensioner in the - direction of the arrow -.






- Remove the ribbed belt from the power steering pump belt pulley and release and remove the tensioner.

• Ribbed belt remains in position on other pulleys.

- Use the hose clamps up to 25 mm diameter. (3094) to clamp off the power steering pump return hose.






- Remove return hose - 1 - from the power steering pump.

- Place a cloth under hydraulic line - 2 - to catch escaping hydraulic fluid.

- Unscrew hydraulic pressure line - 2 - from the power steering pump and place it on top of the longitudinal member.

- Unscrew the belt pulley of the power steering pump for power steering - arrows -.






- Unscrew the bolts - arrows - and remove the power steering pump.






- Remove the power steering pump bracket - arrows -.






• Do not bend or stretch lines or hoses as A/C compressor and refrigerant lines/hoses may be damaged.






- Remove the refrigerant lines from the A/C compressor - arrows -.

Risk of damaging refrigerant lines and hoses.

• Do not stretch, kink or bend refrigerant lines and hoses.

• Seal open pipes and connections on the A/C compressor with caps (to prevent dirt and moisture from getting in).

- Disconnect electrical connector - 1 -.






- Unscrew the bolts - arrows - and remove the A/C compressor.

Installing

Installation is carried out in the reverse order while noting the following:

• An uncertain quantity of refrigerant oil remains in a removed A/C compressor. Therefore, observe the notes for replacing the A/C compressor.

• Observe the notes regarding the removal, installation and start-up of the A/C compressor. Refer to => [ A/C System Operating After Filling Refrigerant Circuit ] A/C System Operating After Filling Refrigerant Circuit.

• The alignment sleeves - A - have different styles (different lengths), make sure to use the correct style. Refer to Electronic Parts Catalog.






• Ensure bushings - A - are properly seated and contact surfaces are clean. Sockets installed incorrectly and dirty or damaged contact surfaces - C - on the bracket or A/C compressor can lead to alignment irregularities between the A/C compressor and engine. Alignment irregularities over operating time lead to damage to the ribbed belt or A/C compressor.

• Secure all hose connections with hose clamps used in series production. Refer to Electronic Parts Catalog.

- Before tightening the A/C compressor, check seating of both alignment bushings - A - in bracket or A/C compressor - B -.

- Attaching the A/C compressor to the bracket

Tightening Specifications






- Attach the refrigerant lines to the A/C compressor.

• Coat the O-ring seals lightly with refrigerant oil prior to installation. Refer to => [ Refrigerant Circuit O-rings ] Refrigerant Circuit O-rings.

- Install the power steering pump.

- Install the ribbed belt.

- Evacuate and fill the refrigerant circuit.

- Install the remaining removed components.

- Check the event memory of the front A/C display control head, the Climatronic control module (J255) , and erase any displayed malfunctions using the Vehicle diagnostic tester in the "Guided Fault Finding" function.

- Operate the A/C system after filling the refrigerant circuit. Refer to => [ A/C System Operating After Filling Refrigerant Circuit ] A/C System Operating After Filling Refrigerant Circuit.

• Note the information regarding operation of the A/C system after filling.