SERVICE MANUAL
CYLINDER HEAD & VALVES
Section 3
Inspect and Repair Cylinder Head as follows:
1.
Visually inspect head for cracks using modern
spraying methods.
a.
Spraying WILL expose hair line cracks or
sand holes.
b.
Spraying WILL NOT show nozzle sleeve
leaks as pressure testing will.
c.
If cracks are found, replace cylinder head.
d.
If NO cracks are found, continue with Step
2.
2.
Pressure test cylinder head as follows:
a.
Fabricate gasket as shown in Fig. 16.Use 3
mm (1/8 in) rubber.
Figure 16. - Thermostat Housing Gasket
b.
Fabricate bottom pressure plate, to cover
water directors, as shown in Fig.17 for 300
and 400 series engines. Use 13 mm (1/2
In} aluminum for a permanent plate or
plywood of the same dimension for a
temporary plate.
c.
Remove valves and install injection nozzles.
d.
Attach fitting to thermostat housing with
pressure gauge. Run hot water at 69-83
kPa (10-12 psi) Into head.
e.
Visually observe head for leakage at:
1.
Injection Nozzle Sleeve Flanges
2.
Upper Deck
3.
Lower Deck
4.
Ports
CGES-185-3
PRINTED IN UNITED STATES OF AMERICA
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