Overview - A/C Compressor Belt Pulley With A/C Clutch -N25-, "DENSO"

-- Perform the preparatory work. Refer to PRELIMINARY WORK FOR REPLACING BELT PULLEY .

-- Remove the belt pulley with the A/C Clutch -N25-. Refer to BELT PULLEY, REMOVING AND INSTALLING .

Fig 1: Exploded View Of Belt Pulley, A/C Compressor With A/C Clutch -N25- "Denso"

Courtesy of AUDI OF AMERICA, LLC

Closure Cap
- Not always present
Clutch Plate
- 30 Nm
- Always replace
- Attached to the A/C compressor input shaft
  -- Clean the contact surfaces on the clutch plate and belt pulley before attaching.
  
  -- Clean the A/C compressor shaft threads before attaching the clutch plate.
  
  -- After tightening, check the gap dimension between the belt pulley and clutch plate and correct it if necessary. Refer to CLUTCH PLATE, REMOVING AND INSTALLING, A/C COMPRESSOR "Denso" (WITH A/C Clutch -N25-) .
  
  NOTE:
  The thread of the new clutch plate has already been greased with a specific amount of a grease by the manufacturer.
- There are different versions.
- The overload protection takes over when the torque is excessive (for example, if the A/C compressor runs with resistance) and the belt pulley runs freely without driving the A/C compressor with the A/C Clutch -N25- switched on.
  Removing and installing
  
  -- Hold the compressor shaft -C- tight and turn the clutch plate counter-clockwise in direction of arrow with a suitable tool to remove as described for the drive plate on an A/C compressor without an A/C clutch. Refer to BELT PULLEY, REMOVING (WITH A/C Clutch -N25-) .
Washer
Spacer
- For adjusting the gap dimension between the clutch and belt pulley
- Check the gap dimension. Refer to GAP DIMENSION BETWEEN BELT AND CLUTCH PLATE, CHECKING, "Denso" A/C COMPRESSOR (WITH A/C Clutch -N25-) .
Circlip
- Replace
- Be careful not to bend the circlip more than necessary when installing it.
  -- Insert the circlip on correct side, the side with beveled insertion edge -A- faces away from A/C compressor (install the flat side facing the A/C compressor).
Belt Pulley
- The belt pulley is sensitive to impact. Be very careful when handling it.
- Clean the flange on the A/C compressor flange before installing the belt pulley.
- There are different versions (depending, for example, on the type of engine).
- Refer to BELT PULLEY, REMOVING (WITH A/C Clutch -N25-) if it is not possible to remove the belt pulley from the flange on the A/C compressor by hand.
Circlip
- Always replace
- Be careful not to bend the circlip more than necessary when installing it.
  -- Insert the circlip on correct side, the side with beveled insertion edge -A- faces away from A/C compressor (install the flat side facing the A/C compressor).
Solenoid Coil
- Make sure the bracket for the cable -B- is installed correctly.
- The connector -D- may be attached to the A/C compressor with a bracket, depending on the version.
- On an A/C compressor where the wires for activating the A/C Clutch -N25- and the A/C Compressor Regulator Valve -N280- are combined in a 3-pin connector, remove the wire to the A/C Clutch -N25- from the connector using an appropriate release tool from the Wiring Harness Repair Set :VAS1978B . Refer to CONTROL MODULES .
- Different versions with or without ground wire to the housing of the A/C compressor.
  NOTE:
  On a solenoid coil without a ground connection wire the ground connection takes place via the housing of the solenoid coil on the connection flange of the A/C compressor. On this version make sure there is a clean corrosion free surfaces, if necessary clean this. Refer to appropriate service information. .
A/C Compressor
- There are different versions depending on engine installed and the vehicle market.
- Clean the A/C compressor flange before installing the belt pulley.
- Clean the compressor shaft thread and then coat the thread lightly with grease.
  NOTE:
  There are different versions depending on the refrigerant (R134a or R1234yf).