TM 5-3805-290-23-1
THEORY OF OPERATION - CONTINUED
0003 00
COOLING SYSTEM
0003 00
1.
General. Engine has a basic cooling system. Cooling system has:
a.
Radiator
b.
Water pump
c.
Oil cooler
d.
Water temperature regulator (thermostat)
2.
Coolant Flow.
a.
Coolant flows from bottom of radiator to centrifugal water pump. Water pump is installed on front of timing case.
Water pump is driven by a gear. Fuel injection pump gear drives water pump gear. Water pump forces coolant
through a passage in timing case to front of cylinder block.
b.
Coolant flow divides as it enters cylinder block. Most coolant flows along right-hand side of cylinder block, then
flows around outside of cylinders to rear of cylinder block.
c.
Remainder of coolant flows along a passage in left side of cylinder block to oil cooler. Coolant flows around oil
cooler element to rear of cylinder block, then to rear of cylinder head.
d.
Coolant flows forward through cylinder head, then flows into water temperature regulator housing. If thermostat is
closed, coolant goes directly through a bypass to inlet side of water pump. If thermostat is open, bypass is closed
and coolant flows to top of radiator.
427-B1508
