Cylinder Head Disassemble

Special Tools

• EN-849:  Assembly Tray
• EN-6167:  Fixing Tool
• EN-6171:  Release Tool
• EN-6215:  Mounting Equipment
• EN-840:  Remover

For equivalent regional tools, refer to Special Tools .

Fig 1: Side Mounts
Courtesy of GENERAL MOTORS CORP.
NOTE: Consider the appropriate screwing on points for the EN-6215-5:  side mounts.
1. Fit EN-6215-5:  side mounts (1) for EN-6215-4:  assembly device.
Fig 2: Assembly Device
Courtesy of GENERAL MOTORS CORP.
2. Install EN-6215-4:  assembly device (1).
Fig 3: Inserting Tap In Spark Plug Thread
Courtesy of GENERAL MOTORS CORP.
3. The spark plug threads must be cleaned of combustion residues to ensure that the counterhold can be attached correctly. Insert tap M14 x 1.25 (1) in the spark plug thread and screw in evenly.
4. Turn the cylinder head baseplate.
NOTE: There are 2 kinds of counter holder. Type A and Type B. Choose the correct type for the existing combustion chamber.
5. Install the counter holder.
Fig 4: Counter Holder Type A
Courtesy of GENERAL MOTORS CORP.
NOTE: Depending upon the combustion chamber organization, it must be used different holders to protect the valves.
6. Counter holder type A (1).
Fig 5: Counter Holder Type B
Courtesy of GENERAL MOTORS CORP.
NOTE: Depending upon the combustion chamber organization, it must be used different holders to protect the valves.
7. Counter holder type B (1).
Fig 6: Mounting Equipment, Fixing Tool And Fixing Bolts
Courtesy of GENERAL MOTORS CORP.
8. Install the EN-6167:  fixing tool (1). Attach the EN-6215-3:  mounting equipment (3) with safety lock pins. Install the fixing bolts (2). Turn the cylinder head baseplate again.
Fig 7: Special Tool On Valve Retainers
Courtesy of GENERAL MOTORS CORP.
9. To ensure that no special tools are damaged during the disassembly of the valve wedges, the valve retainers are to release with EN-6171:  release tool (1). Put the EN-6171:  release tool on the valve retainers and with a short impact of a rubber hammer all valve retainers will loose (setting behavior).
Fig 8: Valve-Spring Depressing Tool
Courtesy of GENERAL MOTORS CORP.
NOTE: The valve-spring depressing tool (1) must be positioned parallel onto the valve spring cap to ensure that neither tools nor components are damaged. Select the appropriate bore in the lever for this purpose. If the valve-spring compressor cannot be positioned parallel, the lever must be adjusted accordingly.
10. Push the depressing tool (1) down with lever until the valve spring cap is released. Remove valve cotters.
Fig 9: Releasing Valve Stem Sealings With Special Tool
Courtesy of GENERAL MOTORS CORP.
11. Remove the upper valve spring cap and valve springs and place them in sequence on EN-849:  assembly tray.

    Release the valve stem sealings by turning with EN-840:  remover (1) and remove from the valve guides.

Fig 10: Valve Box
Courtesy of GENERAL MOTORS CORP.
12. Remove lower valve spring caps or valve rotators from cylinder head and also place on EN-849:  valve box (1).
13. Remove lever tool.
14. Turn cylinder head baseplate. Remove wooden board EN-6215:  mounting equipment and counter holder if attached.
15. Remove all valves in sequence and place on EN-849:  assembly tray (1) in sequence.