TM 9-4940-549-14&P
ENGINE COOLING SYSTEM
GENERAL.
The engine cooling system is a circulating pressure type sy-
stem. It consists of a radiator, a belt driven cooling fan, and a cen-
trifugal water pump, a coolant control thermostat, and a shutter assem-
bly, which is part of the engine enclosure. The water pump receives
coolant from the lower radiator hose and circulates it through the en-
gine, the coolant absorbs heat generated by engine operation. When the
engine reaches normal operating temperature, the coolant control ther-
mostat opens and the coolant returns to the radiator through the upper
radiator hose. As the heated coolant circulates through the radiator,
the cooling fan blows air through the radiator air pasages which dissi-
pates the heat. The shutter assembly blocks the flow of cooling air un-
til the coolant in the radiator reaches normal engine operating tempera-
ture.
RADIATOR.
a.
Removal (Refer to figures 9-1 and 9-2).
(1) Drain the cooling system.
(2) Disconnect radiator coolant lines.
(3) Remove fan guard.
(4) Remove the fan assembly.
(5) Remove the radiator.
Cleaning, Inspection and Repair.
b.
Always wear protective glasses when us-
ing compressed air to clean radiator air
Injury to the eyes may result
passages.
from failure to observe this warning.
(1) Clean foreign particles from the radiator core air passages with
filtered compressed air.
(2) Clean exterior surface of the radiator with cleaning solvent.
(3) Visually inspect the radiator for excessive corrosion, cracked or
broken brazing, and bent cooling fins.
(4) Check interior of radiator for rust and scale deposits.
(5) Test radiator for leaks as follows
