Compressor Clutch: Service and Repair
A/C Compressor Clutch, Removing/Installing
Tools required
Use Mastercool A/C compressor service kit No.91296 or equivalent. Kit contains:
Tool No. Description
90902 Clutch plate puller
90414 Shaft seal seat remover/installer
SD-508 only
90412 0-ring hook
90906 Shaft seal remover/installer
SD-508 only
90910 Compressor shaft protector
91139 Shaft seal seat remover/installer
SD-709 only
91146 Feeler gauges
91138 Shaft seal remover/installer
SD-709 only
90903 Snap ring pliers
90907 Shaft Seal protector
90901 Spanner wrench
Removing
WARNING:
- Follow all recommended safety precautions before performing any A/C system servicing. [1][2]Service Precautions
- Automotive refrigerants containing CFC's are hazardous to the earth's atmosphere. To protect our environment, use an Underwriters Laboratory (UL) approved refrigerant recovery/recycling unit such as Kent-Moore ACR3 or equivalent, whenever discharging an A/C system.
- The A/C system should only be serviced by trained personnel familiar with:
- equipment use
- related safety procedures
- regulations governing the discharging, handling and disposal of automotive refrigerants.
CAUTION:
- Some A/C compressor replacement parts are not available. Always check with your Parts Department for latest parts information before attempting compressor repairs.
- Always follow manufacturer's instructions when using a refrigerant recovery/recycling unit.
- discharge A/C refrigerant system using refrigerant recovery/recycling unit Kent-Moore ACR3 or equivalent.
Note: If the vehicle is received with no refrigerant in the A/C system , always replace the receiver drier.
- remove A/C lines from compressor
- plug A/C lines with a suitable plug to prevent moisture contamination of receiver drier
- remove compressor from vehicle
Note:
- Perform all A/C compressor repairs on a clean dry service bench equipped with a vise.
- When servicing A/C compressors, verify the model number of the compressor, for example SD-709, to insure correct replacement parts are ordered.
- insert spanner wrench (Mastercool tool No. 90901 or equivalent) into clutch plate 18 of compressor
- hold plate 18 stationary with spanner and remove 19 mm hex nut 19 from compressor shaft
- remove front clutch plate 18 with clutch plate puller (Mastercool tool No. 90902 or equivalent similar tool shown)
- if equipped, carefully remove bearing dust cover with screwdriver
CAUTION: Do not distort dust cover when removing.
- remove shaft key 17 by lightly tapping with slotted screwdriver and small hammer
- remove all clutch shims 14, 15, 16 from compressor shaft
- remove bearing snap ring 13 with snap ring pliers (Mastercool tool No.90903 or equivalent)
- remove clutch pulley 12 using puller US 1078
- loosen clutch field coil wire clamp 10 and connector holder, if equipped
- remove clutch field coil retainer snap ring 11 with snap ring pliers (Mastercool tool No.90903 or equivalent)
- remove clutch field coil 9
Installing
- install clutch field coil 9
- clutch field coil flange protrusion must match hole in front of compressor housing to prevent coil movement and to correctly locate power leads for attachment
- install clutch field coil retainer snap ring 11 with snap ring pliers
- attach field coil wire clamp 10 and connector holder, if equipped
- support compressor in bench vise on mounting tabs at base of compressor
- align pulley 12 on front housing hub squarely
- place driver kit VW 519 on pulley
- ensure outer edge of driver ring rests firmly on inner race of pulley bearing
- while guiding pulley 12 to prevent binding, tap end of VW 519 with small hammer until pulley bottoms out against compressor front housing hub
- as an alternate method, press pulley onto compressor shaft using spacers VW 412 and VW 473
- install snap ring 13 with snap ring pliers (Mastercool tool No.90903 or equivalent)
- install shims 14, 15, 16
- install shaft key 17 using small hammer and screwdriver
- install bearing dust cover, if equipped
- align front clutch plate keyway to compressor shaft key 17
- install front clutch plate 18 onto compressor shaft
- install shaft protector (Mastercool tool No.90910 or equivalent) onto compressor shaft and tap with a small hammer until clutch plate 18 bottoms on shims 14, 15, 16
- install 19 mm hex nut 19 onto compressor shaft
- insert spanner wrench (Mastercool tool No. 90901 or equivalent) into holes of front clutch plate 18 and hold stationary
CAUTION: Use a beam type torque wrench. Damage may result from use of inaccurate "click" wrenches.
- tighten hex nut 19
- 30-34 Nm (22-25 ft lb)
Note: Air gap a is determined by spacer shims 14,15,16. When installing a clutch assembly, try the original shims first. When installing a new clutch on a new compressor use the 1 mm, 0.5 mm, and the 0.127 mm shims provided in the clutch installation kit. If the air gap does not meet specification, add or remove shims accordingly.
- check air gap a of clutch with feeler gauge (Mastercool tool No.91146 or equivalent)
- a = 0.400 mm to 0.800 mm gap (0.016 in. to 0.031 in.)
Note: If air gap a is not consistent around the circumference, lightly pry up on the front face plate at the low spots and lightly tap down on the high spots with a small hammer.
- lubricate all 0-rings with clean refrigerant oil
- install compressor in vehicle
- remove plugs from A/C lines.
- install A/C lines (arrows) on compressor and tighten as follows:
- suction line: 35 Nm (26 ft lb)
- discharge line : 25 Nm (18 ft lb)
- install and properly tension compressor drive belt
- evacuate and charge A/C system
- check compressor clutch and A/C system for proper operation