CYLINDER HEAD AND VALVE TRAIN 125
Cleaning
Cylinder Head
CAUTION: To prevent engine damage, leave the
valves installed within the cylinder head. This protects
the valve seats during the cleaning process.
1. Use a rotary wire brush or a sanding block with
mineral spirits to remove any deposits and gasket
material from the gasket surface of the cylinder
head.
2. Useanappropriatelysizedbrushtocleanall
mounting bolt holes in the cylinder head.
3. Wash rocker arm assemblies, hydraulic lifters,
and push rods in a suitable solvent and dry them
thoroughly. Replace any bolts that have damaged
threads.
CAUTION: To prevent engine damage, do not use
chlorinated solvents on bolts or crankcase tapped
holes. Parts should be clean, dry, and free of any
chemical residuals other than engine oil.
Inspection
Valve Train Components
Engine valve train load carrying requ
irements have
resulted in the release of several di
fferent push rod
and tappet configurations. The main d
ifferences are
improved geometry designs and mate
rials.
For information on push rod and tapp
et compatibility
for different engine model year con
figurations, see
(TSI-06-12-14 Update Valve Tra
in Components –
Push Rod and Tappet Compatibil
ity, page469).
Push Rods
WARNING: To prevent personal
injury or
death, wear safety glasses
with side shields.
Limit compressed air pres
sure to 207 kPa (30 psi).
1. Thoroughly clean each pus
hrodusingasuitable
solvent and dry rods using
filtered compressed air
.
2. Inspect each push rod for wear at both ends. If
push rod is worn, install new push rod.
Figure 148 Check push rods for straightness
3. Check all push rods for straightness by rolling
push rods on a flat surface with the cap end over
theedgeoftheflat surface.
4. Measure push rod runout with a feeler gauge
(page156) between the flat surface and push rod.
5. If specifications (page 154) are exceeded, install
new push rod.
Rocker Shaft
CAUTION: To prevent engine damage, if it is
necessary to replace the rocker shaft, all of the
rocker arms must be replaced. Reusing rocker arms
on a new shaft will not allow for an adequate break-in
period, causing premature failure of the rocker arm
assembly.
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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