TM 5-2410-241-23-1
0007
COOLING SYSTEM
0007
Engine Cooling System
0007
The engine cooling system consists of the following components:
Transmission oil cooler
Engine oil cooler
Cylinder head
Cylinder liner
Temperature regulator (thermostat)
The gear driven water pump (Figure 1, Item 7) is located on the right hand side of the front timing gear housing.
The water pump pulls the antifreeze coolant solution from the bottom of radiator (Figure 1,
Item 5). The rotation of the water pump's impeller creates coolant flow within the cooling system.
The water pump impeller is rotated at 1.17 times the engine speed by an idler gear, which is turned by the
crankshaft gear. The water pump shaft is supported by two ball bearings. One ball bearing is located in the water
pump housing; the other ball bearing is located in the front timing gear housing. The water pump impeller face is
open. The impeller vane is radial. The impeller is made out of cast iron. The rear cover is made out of die cast
aluminum. The water pump uses a cartridge seal located on the inlet side of the pump in order to provide good
water flow around the seal for cooling.
The antifreeze coolant solution is pumped through the engine oil cooler (Figure 1, Item 1) to the transmission
cooler (Figure 1, Item 8) and into the supply manifold (Figure 1, Item 9), which is located in the cylinder block. The
supply manifold distributes the antifreeze coolant solution at each cylinder. The antifreeze coolant solution then
flows around the upper portion of the cylinder liner (Figure 1, Item 10), which cools the upper portion of the cylinder
liner. At each cylinder, the antifreeze coolant solution flows from the cylinder liner to the cylinder head (Figure 1,
Item 2). The cylinder head is divided into single cylinder cooling sections. In the cylinder head, the antifreeze
coolant solution flows across the center of the cylinder and across the injector seat boss. At the center of the
cylinder, the antifreeze coolant solution flows around the injector sleeve over the exhaust port. The antifreeze
coolant solution then exits into the return manifold (Figure 1, Item 4), which collects the antifreeze coolant solution
from each cylinder and directs the flow to the temperature regulator housing (Figure 1, Item 3). When the
temperature regulator is in the closed position, the antifreeze coolant solution flows through the regulator, allowing
it to flow through the bypass tube (Figure 1, Item 6) directly back to the water pump. The water pump then
recirculates the antifreeze coolant solution. With the temperature regulator in the open position, the antifreeze
coolant solution is directed through the radiator and then back to the water pump inlet.
0007-2
