CYLINDER HEAD AND VALVE TRAIN 127
Cylinder Head Warpage
Figure 151 Checking for warpage
Figure 152 Checking pattern
Use a straightedge and feeler gauge to check the
gasket surface of the cylinder head for warpage.
Use the checking pattern that is shown. If warpage is
present as indicated by a feeler gauge measurements
exceeding cylinder head gasket surface flatness
specifications, check thickness of cylinder head.
Cylinder Head Thickness
Figure 153 Checking cylinder head thickness
Usea6-7inchoutsidemicrometertomeasure
the thickness of the cylinder head at six locations
(four corners and two center points). Cylinder
head thickness must equal or exceed the minimum
specification after resurfacing. If the minimum
specification after resurfacing cannot be met, replace
cylinder head.
Valve Seat Leakage
NOTE: This test does not check for the condition of
the valve guides or the valve stem-to-valve guide
clearance.
1. Position the cylinder head on wood blocks with the
gasket surface facing down.
2. Squirt mineral spirits into the intake and exhaust
valve ports and wait 5 minutes.
3. Use an inspection mirror to check valve seat area
for leakage of the mineral spirits past the valve
seats.
NOTE: If leakage occurs, the valves must be
reconditioned.
EGES-265-2
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
Follow all warnings, cautions, and notes.
© 2009 Navistar, Inc.
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