Section VIII. ORGANIZATIONAL MAINTENANCE PROCEDURES
3-57. Inspection and Test
3-56. General
The instructions in this section, and all subsequent
All inspection and test requirements outlined in
maintenance allocation chart for organizational level are
paragraphs and sections, are published for the
information and guidance of organizational maintenance
covered in the paragraphs describing other maintenance
procedures within the system.
personnel in maintaining the crane shovel.
Section IX. ENGINE CYLINDER HEAD AND VALVE MECHANISM
engine oil to crankcase, if necessary (LO 5-3810-201-
3-58. General
12).
a. Model 687C-18-ES Engine. On this two cycle
b. Removal and Installation, Model D333TA Engine.
diesel engine the cylinder head forms the top of the
(1)Remove the six bolts, flatwashers, and seals that
combustion chamber and contains passages for the
secure valve cover to cylinder head, remove valve
intake of air and the expulsion of gases. The exhaust
cover, and inspect gasket.
valve mechanism is attached to the head. The rocker
(2)Replace a defective gasket seal, then carefully
arm, which directly operates the exhaust valve, operates
install valve cover. Be sure gasket fits recess in valve
on a short shaft mounted in two supports on the cylinder
cover, then install six seals in top of valve cover,
head. Valve lash adjustment is accomplished with the
position flatwashers on bolts, install bolts through seals,
adjustable ball-ended screw in the rocker arm.
and tighten to between 12 and 18 foot-pounds torque.
b. Model D33TA Engine. On this four cycle diesel
(3)Start engine (para 2-10), and run until engine
engine the valves and valve mechanism admit inlet air
reaches operating temperature, checking for oil leaks at
and release exhaust gases at precisely timed intervals
gasket and seals. Stop engine (para 2-11), correct any
during engine operation. The inlet valve is open during
leaks, then add engine oil to crankcase if necessary (LO
inlet stroke of piston to permit air to enter cylinder. After
5-3810-20112).
the power stroke, the exhaust valve is opened to permit
piston to force burned gases from the cylinder as it
3-60. Valve (Rocker Arm) Adjustment
moves upward in the exhaust stroke.
a. General.
The valve adjustment may be
c. Differences.
There are other changes in
accomplished with engine hot, or cold. But when
configuration between the two engines, in addition to
adjusted cold, final adjustment must be made while hot.
quantity of valves and stroke cycles, which will be
These instructions will cover valve adjustment on a hot
covered in the applicable maintenance paragraphs.
engine (water temperature between 160F and 180F).
b. Model 687C-18-ES Engine Valve Adjustment.
3-59. Valve Cover and Gasket
(1)Remove valve cover (para 3-59).
a. Removal and Installation, Model 687C-18ES
(2)Start engine (para 2-10) and run until operating
Engine.
temperature is reached (between 160 and 180 F).
(1)Turn three locking handwheels securing cover
(3)When engine is at operating temperature, stop
counterclockwise until they are loose, then remove
engine (para 2-11), with cylinder No. 1 at top dead
valve cover from cylinder head.
center (valve seated closed) Use wrench (fig. 3-42) to
(2)Remove valve cover gasket from cylinder head
loosen locknut holding valve adjusting screw.
(or cover) and discard.
(4)Use screwdriver and turn adjusting screw until a
(3)Install new valve cover gasket on cylinder head;
clearance of 0.012 inch (hot) to 0.014 inch (cold) is
position valve cover on gasket, then secure by turning
obtained with thickness gage.
the three locking handwheel clockwise until they are
Note: When engine temperature is at 130 F or
tight.
below, it is considered to be a cold engine.
(4)Start engine (para 2-10), run until engine reaches
(5)When clearance is correct, hold adjusting screw
operating temperature, checking for oil leaks at gasket.
with screwdriver and tighten the locknut.
Stop engine (para 2-11); correct any leaks, then add
(6)Recheck clearance. Readjust if necessary.
3-52
