Compressor Clutch: Service and Repair

A/C Clutch -N25-, Servicing


CAUTION! DO NOT open the A/C refrigerant system to service the A/C clutch. Instead remove the compressor from the mounting bracket.







1 - Clutch plate lock nut
- Always replace
- 15 Nm (11 ft lb)
2 - Clutch plate
3 - Shims
- For adjusting gap between clutch plate and belt pulley
- Gap: 0.4-0.6 mm (0.016-0.024 in.)
4 - Circlip
- Always replace
- Must be installed correctly (flat side toward compressor)
- Must be properly seated in groove
5 - Ribbed belt pulley
- Clean contact surfaces before installing


CAUTION! Before removing ribbed belt, mark the running direction. The belt could break if allowed to run in the reverse direction.


6 - Circlip
- Always replace
- Must be installed correctly (flat side toward compressor)
- Must be properly seated in groove
7 - Magnetic coil
- Installed with a fuse which interrupts the operation of the coil if it becomes too hot (e.g. if the compressor is not moving freely).
- Contains protection diode -J201- for suppressing voltage peaks which may occur when the A/C clutch -N25- is disengaged.
8 - Retaining clip with bolt
9 - Retaining clip
10 - Retaining clip
11 - Screw
12 - A/C compressor
- Sanden SD7 - V16
13 - Threaded bushing


Fig. 1 Clutch plate lock nut, removing and installing







Tightening torque: 15 Nm (11 ft lb)


NOTE:
- Use commercially available two-pin wrench (illustrated) to counterhold clutch plate.
- Always replace lock nut.


Fig. 2 Clutch plate, removing







- Pry off carefully using two screwdrivers -A-.


NOTE: If the clutch plate is installed too tightly, use a commercially available two-arm or three-arm puller to remove the clutch plate.


Fig. 3 Ribbed belt pulley, removing







- Attach commercially available two-arm puller -A- at shoulder -B- and remove pulley.


NOTE:
- To avoid damaging pulley when removing, make sure the puller is properly fitted to shoulder -B-.
- Clean contact surface before installing.
- If necessary, carefully tap the pulley into place using a plastic hammer and a suitable drift (applied to the bearing inner race).


Fig. 4 Installing magnetic coil







- Fit lug -C- into recess on magnetic coil -A-.
- Make sure wiring harness -B- is correctly positioned in relation to magnetic coil -A-.


Fig. 5 Checking and adjusting gap







Gap width = difference between distance "1" and distance "2" measured as follows:

- Measure distance "1" between belt pulley and clutch plate using depth gauge -A- (at three different points).
- Apply 12 V to magnetic coil:
- B+ terminal to single-pin connector
- -D- Ground (GND) to compressor housing
- Measure distance "2" between belt pulley and clutch plate using depth gauge -A- (at three different points).

Gap width (distance "1" - distance "2") must be 0.4-0.8 mm.


NOTE:
- The gap width must be within the tolerances around the whole circumference.
- The gap width can also be measured without removing the compressor (compressor installed).
- If the gap width is outside the specified tolerance, remove the clutch plate and adjust the gap width by removing or adding shims.