Special Tools

• EN-8062:  Valve Spring Compressor
• EN-9666:  Valve Spring Tester
• EN-43963:  Valve Spring Compressor (off car)

For equivalent regional tools, refer to Special Tools .

Fig 1: Identifying Cylinder Head Plugs
Courtesy of GENERAL MOTORS CORP.
CAUTION: In order to avoid damage, install the spark plugs after the cylinder head has been installed on the engine.
1. Install NEW cylinder head plugs (1). Coat the plugs with sealer. Refer to Adhesives, Fluids, Lubricants, and Sealers .
2. Inspect the valve springs for the following conditions:
   • Expanded height
   • Unparallel spring ends
   • Spring tension using EN-9666:  tester
   • Any distorted springs should be replaced
Fig 2: View of Valve Runout
Courtesy of GENERAL MOTORS CORP.
3. Inspect the valves and the valve seats. Refer to Valve and Seat Grinding .
Fig 3: View of Valves
Courtesy of GENERAL MOTORS CORP.
4. Install the valves (1). Replace any valves, if required.
Fig 4: View of Valve Seals
Courtesy of GENERAL MOTORS CORP.
NOTE: Always use NEW valve stem oil seals when assembling the cylinder head.
5. Install the new valve seals (1). Fully seat the seals on the valve guides.
Fig 5: View of Valve Springs
Courtesy of GENERAL MOTORS CORP.
6. Install the springs (1).
Fig 6: View of Valve Keys and Retainer
Courtesy of GENERAL MOTORS CORP.
WARNING: Compressed valve springs have high tension against the valve spring compressor. Valve springs that are not properly compressed by or released from the valve spring compressor can be ejected from the valve spring compressor with intense force. Use care when compressing or releasing the valve spring with the valve spring compressor and when removing or installing the valve stem keys. Failing to use care may cause personal injury.
CAUTION: Do not compress the valve springs to less than 24.0 mm (0.943 in). Contact between the valve spring retainer and the valve stem oil seal can cause potential valve stem oil seal damage.
7. Install the retainers (1).
8. Using the EN-8062:  compressor and the EN-43963:  compressor (off car), compress the valve spring.
9. Install the valve keys.
10. Slowly release the EN-8062:  compressor and the EN-43963:  compressor (off car) from the valve/spring assembly.
11. Inspect for proper valve key seating.
12. Install the remaining valves, springs, and other components.
Fig 7: Identifying the Coolant Air Bleed Hose Fitting
Courtesy of GENERAL MOTORS CORP.
CAUTION: Refer to Fastener Caution .
13. Install the cylinder head air bleed tube (1) and tighten the tube to 15 N.m (11 lb ft).