Hummer H1 Service Manual page 110

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EXHAUST VALVE
PRE-COMBUSTION CHAMBER
Figure 2-135: Pre-combustion Chamber Removal
Figure 2-136: Cover Removal/Installation
05745159
INTAKE VALVE
VALVE STEM SEAL
VALVE STEM SEAL
VALVE STEM AND
GUIDE SEAL
VALVE SPRING AND
DAMPER ASSEMBLY
Figure 2-134: Intake and Exhaust Valve Components
CYLINDER HEAD
COVER
GASKET
VALVE SPRING AND
DAMPER ASSEMBLY
SHIM
SHIM
SHIELD
Cleaning and Inspection
Clean the cylinder heads and valve components in parts clean-
ing solvent. Use carb cleaner and a wire brush to remove stub-
born carbon deposits on the heads valves and prechambers.
Check flatness of intake/exhaust manifold seating surfaces
with straightedge. Surfaces must be flat to within 0.006 in.
(0.15 mm).
Check cylinder head flatness with straightedge and feeler
gauge (Figure 2-137). Overall (end-to-end) flatness should not
vary by more than 0.006 in. (0.152 mm). Replace the head if
warped or distorted. Do not machine the head.
FEELER
GAUGE
Figure 2-137: Checking Cylinder Head Flatness
Inspect the combustion prechambers (Figure 2-138). Minor
cracks under 3/16 in. (0.48 mm) in length are not cause for re-
placement. Install new chambers only when cracks extend be-
yond the indicated length (Figure 2-138).
Engine
RETAINER
SHIELD
RETAINER/ROTATOR
STRAIGHT EDGE
2-73
LOCKS