ENGINE COOLING SYSTEM
c. Cleaning, Inspection, and Repair.
(1) Clean all parts with dry cleaning solvent
The engine cooling system is a circulating pres-
(Federal Specification P-D-680) and dry thoroughly.
mare type system. It cosists of a radiator, a belt
driven cooling fan and centrifugal water pump, a
(2) Visually inspect housing and flange for
coolant control thermostat, a thermostatically con-
cracks, breaks, corrosion, and other damage.
trolled shutter assembly, and a protective grille.
The water pump receives coolant from the lower
radiator hose and circulates it through the engine
(3) Inspect shafts and pin for scores, deep
water pattens and other damage.
cylinder block and cylinder head. As it circulates
through the engine, the coolant absorbs heat gener-
(4) Inspect manual control arm for cracks,
ated by engine operations When the engine reaches
corrosion and excessive wear.
normal operating temperature, the coolant control
thermostat opens and the coolant returns to the
radiator through the upper radiator hose. As the
(5) Check springs for cracks, corrosion,
breaks, chaffing and distortion.
heated coolant circulates through the radiator, the
cooling fan blows air through the radiator air pass-
(6) Inspect lever for cracks, corrosion, and
ages which dissipates the heat. The shutter assem-
bly blocks the flow of cooling air until the coolant
in the radiator reaches normal engine operating
(7) Inspect bushings for scores and excessive
(8) Refer to the Operator and Organizational
Maintenance Manual and test thermostat.
Refer to the Operator and Organizational Main-
tenance Manual for grille maintenance instructions.
(9) Replace any damaged or defective parts.
3-26. SHUTTER CONTROL ASSEMBLY.
d. Assembly. Assemble shutter control assem-
bly in reverse order of disassembly procedures.
a. Removal Refer to the Operator and Organi-
zational Maintenance Manual for shutter control as-
e. Installation. Refer to the Operator and Or-
sembly removal instructions.
ganizational Maintenance Manual for shutter control
washers (2) to remove housing (3), gasket (4), ther-
mostat (5), nut (6) and piston (7). Discard gasket.
a. Removal. Refer to the Operator and Organi-
zational Maintenance Manual for radiator removal
(2) Remove and discard packing (8).
(3) Remove retaining rings (9) and loosen set-
b. Cleaning, Inspection, and Repair.
screws (10) to remove shaft assembly (11). Do not
disassemble setscrews (12), cam (19) and shaft (14)
unless inspection reveals damage.
(4) Remove bushings (15).
Always wear protective glasses when using
compressed air to clean radiator air pass-
(5) Remove retaining rings (16) to remove
ages. Injury to the eyes may result from
shaft (17), lever (18) and bushings (19).
failure to observe this warning.
(6) Remove retaining ring (20) to remove act-
uator pin (21) with assembled parts.
(1) Clean foreign particles from radiator core
air passages with filtered compressed air.
(7) Remove retainer, spring (29) and
washers (24, 25, and 26) from actuator pin.
(2) Clean exterior surface of radiator with dry
cleaning solved (Federal Specification P-D-680).
(8) Remove nut (27), spring (28), screw (29),
(3) Visually inspect radiator for excessive
and flat washer (30) to remove manual control arm
corrosion, cracked or broken brazing, and bent cool-
(31) from flange (32).