ARMY TM 9-6115-464-12
AIR FORCE TO 35C2-3-445-1
NAVY NAVFAC P-8-624-12
Section IX. UNIT MAINTENANCE OF THE ENGINE COOLING SYSTEM
4-35 GENERAL. This section contains unit maintenance instructions for the engine cooling system. The cooling sys-
tem consists of a radiator, a belt driven cooling fan and water pump, a coolant control thermostat and a thermostatically
controlled shutter assembly. The water pump forces coolant through passages in the engine block and cylinder heat
where it absorbs heat generated by engine operation. When the engine reaches normal operating temperature, the
coolant control thermostat opens and the heated coolant flows through the upper radiator hose assembly into the radia-
tor where the heat is disipated. The cooling fan circulates air through the air passages of the radiator where it absorbs
heat from the coolant tubes. The shutter assembly blocks the flow of cooling air through the radiator until the engine
has reached normal operating temperature. It is equipped with a manual control which maybe used in the event that
the shutter control thermostat or linkage fails to function properly.
4-36 GRILLE.
a.
Removal. Remove nuts (1, Figure 4-23), Iockwashers (2), screws (3), flatwashers (4) and remove grille (5).
b. Cleaning and Inspection.
(1) Clean grille with a mild soap and water solution, rinse with clean water and dry thoroughly.
(2) Inspect grille for cracks, corrosion, broken welds, dents, and other damage.
c.
Repair.
(1) Repair grille by straightening cross members and removing minor dents.
(2) Replace grille if damaged beyond simple repair.
d. Installation. Install grille (5, Figure 4-23), flatwashers (4), screws (3), lockwashers (2), and nuts (1).
4-37 SHUTTER CONTROL THERMOSTAT.
a.
Removal.
(1)
(2)
(3)
(4)
(5)
(6)
(7)
Drain radiator and disconnect radiator hoses (paragraph 3-27).
Loosen damp (6, Figure 4-23) and remove drain tube (7).
Remove cotter pin (8) to disconnect shutter control linkage.
Remove screws (9) and Lockwashers (10) to remove control assembly and gasket (11 ). Discard gasket.
Remove screws (12) to separate thermostat housing (13) from linkage (14).
Remove gasket (15) and thermostat (16). Discard gasket.
Do not remove drain cock (17) and adapter bushing (18) unless damage is present and replacement
is necessay.
b. Cleaning and Inspection.
(1) Clean shutter control thermostat with an approved solvent and dry thoroughly.
(2) Inspect thermostat for cracks, corrosion, and other damage.
(3) Inspect shutter control assembly for cracks, corrosion, bent manual control lever and other damage.
4-59
