CYLINDER HEAD DISASSEMBLY
Mark valves for location. Using valve spring compressor, compress valve springs. Remove valve locks.
Carefully release spring compressor. Remove retainer or rotator, valve spring, spring seat and valve. See Fig. 2 .
Fig. 2: Exploded View of Valve Assemblies
CYLINDER HEAD CLEANING & INSPECTION
Clean cylinder head and valve components using approved cleaning methods. Inspect cylinder head for cracks,
damage or warped gasket surface. Place straightedge across gasket surface. Determine clearance at center of
straightedge. Measure across both diagonals, longitudinal center line and across cylinder head at several points.
See Fig. 3 .
On cast iron cylinder heads, if warpage exceeds .003" (.08 mm) in a 6" span, or .006" (.15 mm) over total
length, cylinder head must be resurfaced. On most aluminum cylinder heads, if warpage exceeds .002" (.05
mm) in any area, cylinder head must be resurfaced. Warpage specification may vary by manufacturer. If
warpage exceeds specification on some cylinder heads, cylinder head must be replaced.
Cylinder head thickness should be measured to determine amount of material which can be removed before
replacement is required. Cylinder head thickness must not be less than the manufacturer's specification.
If cylinder head required resurfacing, it may not align properly with intake manifold. On "V" type engines,
misalignment is corrected by machining intake manifold surface that contacts cylinder head. Cylinder head may
be machined on surface that contacts intake manifold. Using oil stone, remove burrs or scratches from all
sealing surfaces.
1998 Chevrolet Pickup C1500
GENERAL INFORMATION Engine Overhaul Procedures