Figure 4-9. Crane engine cylinder head assembly, exploded view.
f. Inspect cylinder head surface for scratches,
4-42. Cleaning, Inspection and Repair
etching or other damage. Resurface head or replace as
a. Clean all parts with an approved cleaning solvent
Minimum permissable height after
and dry thoroughly.
resurfacing is 4.970 inches.
b. Test the cylinder head for leaks. Check carefully
around the valve and injector seats for cracks. Discard
any part cracked at the seats.
Refer to figure 4-9 and reassemble the cylinder head
c. Inspect cylinder head examining fuse plugs,
valve seats, and injectors sleeves for signs of
overheating, looseness, excessive wear or other
a. Install cylinder head assembly as shown on
damage. Replace part as necessary.
b. Torque the cylinder head capscrews in
Cylinder heads are equipped with
(1) Tighten all capscrews to 25 ft-lbs.
fuse plugs containing a metal-alloy
(2) Continue to tighten capscrews in 100 ft-
center that melts if the engine is
lbs. increments to 300 ft-lbs.
overheated. Examine fuse plugs for
(3) Then tighten capscre,ws in 50, ft-lbs.
signs of overheating. If metal-alloy
increments to 390,'400 ft-lbs.
has melted, as
c. Install the valve cross heads on the guides.
d. Install rocker lever assembly and injectors (para
d. Inspect valves for cupped, pitted or worn
condition. Replace or grind valves as necessary.
e. Inspect valve springs and valve guides for
excessive wear and replace defective parts.