Dodge RAM 1500 1998 Owner's Manual page 1475

9 - 252 ENGINE 5.9L DIESEL
CYLINDER HEAD (Continued)
CLEANING—PUSHRODS
Clean the pushrods in a suitable solvent. Rinse in
hot water and blow dry with compressed air. If nec-
essary, use a wire brush or wheel to remove stubborn
deposits.
INSPECTION
INSPECTION - CYLINDER HEAD
Inspect the cylinder head for cracks in the combus-
tion surface. Pressure test any cylinder head that is
visibly cracked. A cylinder head that is cracked
between the injector bore and valve seat can be pres-
sure tested and reused if OK; however, if the crack
extends into the valve seat insert bore, the cylinder
head must be replaced.
Visually inspect the cylinder block and head com-
bustion surfaces for localized dips or imperfections.
Check the cylinder head and block combustion sur-
faces for overall out-of-flatness. If either the visual or
manual inspection exceeds the limits, then the head
or block must be surfaced.
Check the top surface for damage caused by the
cylinder head gasket leaking between cylinders.
Inspect the block and head surface for nicks, ero-
sion, etc.
Check the head distortion. Maximum overall vari-
ation end to end is 0.305 mm (0.012 inch) (Fig. 13),
and maximum overall variation side to side 0.076
mm ( .003 in.).
DO NOT proceed with the in-chassis overhaul if
the cylinder head or block surface is damaged or not
flat (within specifications).
Check block surface for distortion. Maximum vari-
ation end-to-end is 0.076 mm ( .003 in.), side-to-side
0.051 mm (.002).
Fig. 13 Cylinder Head Combustion Deck Face
1 - STRAIGHT EDGE
2 - FEELER GAUGE
Visually inspect the cylinder head bolts for dam-
aged threads, corroded/pitted surfaces, or a reduced
diameter due to bolt stretching.
If the bolts are not damaged, their "free length"
should be measured using the cap screw stretch
gauge provided with the replacement head gasket.
Place the head of the bolt against the base of the slot
and align the bolt with the straight edge of gauge
(Fig. 14). If the end of the bolt touches the foot of the
gauge, the bolt must be discarded. The maximum
bolt free length is 132.1 mm (5.200 in.).
Fig. 14 Head Bolt Stretch Gauge
INSPECTION—CROSSHEADS
Inspect the crossheads for cracks and/or excessive
wear on rocker lever and valve tip mating surfaces
(Fig. 15). Replace any crossheads that exhibit abnor-
mal wear or cracks.
Fig. 15 Inspecting Crosshead for Cracks
DR