Servicing magnetic coupling -N25- with compressor removed; Denso — VW

Required special tools, workshop equipment, test and measuring devices and aids

Not shown:

Commercially available two-arm puller, e.g. Kukko 20-10 with hooks with 100 mm clamping depth.
Commercially available strap spanner
Depth gauge

Please carry out the following work first:

Evacuate refrigerant with service station V.A.G 1885.

Note:

It is punishable by law to drain off refrigerant into the environment.

Remove A/C compressor from bracket
=> Removing and installing A/C compressor bracket.

Combi hex bolt
Renew
15 Nm
Removing and installing => Fig.
1

Coupling pulley
Pulling off =>Fig.
2
Checking gap dimension =>Fig.
4

Shims
For adjusting gap dimension between coupling and belt pullies
Gap dimension: 0.4 - 0.6 mm
Checking gap dimension =>Fig.
4

Circlip
Renew

Install facing proper direction:
Flat side faces compressor

Ensure proper seating in groove

Belt pulley
Pull off with commercially available two or three-arm puller.

To prevent the belt pulley from being damaged, please ensure proper seating of the puller.

Circlip
Renew

Install facing proper direction:
Flat side faces compressor

Ensure proper seating in groove

Magnetic coil
Installing =>Fig.
3

Note:

An overheating fuse is integrated in the magnetic coil. The overheating fuse interrupts the magnetic coil as soon as (for example, due to a sticky compressor) the magnetic coupling becomes too hot.

Screw
Compressor
Manufacturer: Denso
Table of compressor manufacturers: => page
87-61

Removing magnetic coupling from compressor and mounting again

Fig.1
Loosening and tightening combi hex bolt

Unscrew combi hex bolt.
Tightening torque: 15 Nm

Please use a commercially available strap spanner -A- with a fabric band to brace.

Fig.2
Pulling off coupling pulley

Carefully loosen coupling pulley with two screwdrivers and remove.

If the coupling pulley is stuck, please use a commercially available two or three-arm puller.

Fig.3
Installing magnetic coil

Place magnetic coil on compressor.
Position locking pin -A- in recess.

Fig.4
Checking and adjusting gap dimension

Gap dimension: 0.4 - 0.6 mm

Determine dimension 1"

Measure between belt pulley and coupling pulley with depth gauge -C- and note dimension.

Please conduct three measurements at different points. The dimension must be the same at all points.

Determine dimension "2"

Separate connector -A- on compressor.
Connect connector -A- to vehicle battery (terminal +).
Measure between belt pulley and coupling pulley with depth gauge -C- and note dimension.
Determine gap dimension.

The gap dimension results from the difference between dimension "1" and dimension "2".

Note:

The gap dimension must be within the specified tolerance around the entire circumference.
The gap dimension can also be measured with the compressor installed.
If the gap dimension is outside the specified value, remove the coupling pulley and adjust the gap dimension by removing or inserting shims.