LEAKING HYDRAULIC CLUTCH CYL. REPLACE HYDRAULIC SYSTEM

TRANSMISSION MODELS: VEHICLE APPLICATIONS: 1989 'Y' CARS Bulletin Covers:

Some 1989 Corvettes with ZF 6 speed transmissions built before VIN breakpoint K5116286 may exhibit higher than normal shift efforts and/or shift clash. These conditions are most likely caused by loss of full clutch disengagement due to a leaking hydraulic actuator (slave cylinder) assembly.

To repair this condition install a new hydraulic clutch actuator and master cylinder assembly in the vehicle. The complete hydraulic system must be replaced because of system contamination caused by the leaking/worn actuator (slave) cylinder. Replacement of the actuator (slave) cylinder alone will only result in a temporary fix to the customer.

The new hydraulic assembly will come as a prefilled unit which will not require any bleeding.

Service Procedure:

1. Place vehicle on hoist and disconnect battery.

2. Remove (4) left side fender screws for access for battery removal.

3. Remove cruise control servo and lay aside (3 screws).

4. Remove cruise control servo bracket (2 bolts).

5. Remove battery (1 bolt).

6. Remove under dash hush panel and disconnect lamp wire (3 screws and 1 nut).

7. Remove dash brace (2 bolts).

8. Disconnect clutch master cylinder push rod at clutch pedal (1 clip).

9. Remove clutch master cylinder bolts (2) and pull out from dash.

10. Remove (1) hydraulic line clamp screw at front of dash.

11. Raise vehicle.

12. Remove (1) hydraulic line clamp bolt at clutch housing.

13. Remove (2) slave cylinder retaining nuts and pull out of clutch housing.

14. Disconnect ground wires at clutch housing (1 nut).

15. Lower vehicle.

16. Pull hydraulic clutch system out of engine compartment.

17. Route new hydraulic clutch system in engine compartment.

18. Install clutch master cylinder to front of dash (2 bolts).

19. Raise vehicle.

20. Install slave cylinder to clutch housing (2 nuts).

21. Install (1) hydraulic line clip bolt at clutch housing.

22. Install ground wires at clutch housing (1 nut).

23. Lower vehicle.

24. Install (1) hydraulic line clip screws at front of dash.

25. Install battery.

26. Install cruise control servo bracket (2 bolts).

27. Install cruise control servo (3 screws).

28. Install (4) left side fender screws and align.

29. Connect clutch master cylinder to clutch pedal (1 clip).

30. Install dash brace (2 bolts).

31. Connect lamp wire and install under dash hush panel (3 screws and 1 nut).

32. Reconnect battery.

33. Check hydraulic clutch operation.

Service Parts:

Part Number Description ----------- ----------- 10085205 Cylinder Assembly - Clutch Master and Actuator

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.