WASHER-THRUST 8D4208 - Caterpillar

Illustration 1 g02180915
(1) Jacket water pump
(2) Engine oil cooler
(3) Block
(4) Cylinder head
(5) Water manifold
(6) Water temperature regulator housing
(7) Tube
(8) Bypass tube
(9) Radiator or heat exchanger Coolant flows to the jacket water pump (1) through an elbow that connects to the radiator or heat exchanger (9). The coolant is sent through the engine oil cooler (2).Note: There is one opening on the pump outlet so that a remote pump can be connected to the system. The remote pump can be used if there is a failure of the pump on the engine.The coolant flows into a passage in the block. The passage is near the center of the vee at the rear of the block. The coolant flows through the oil cooler into the water jacket of the block at the right rear cylinder. The coolant flows to both sides of the block through distribution manifolds. The distribution manifolds are connected to the water jacket of all the cylinders. The main distribution manifold is located just above the main bearing oil gallery.The coolant flows upward through the water jackets. The coolant flows around the cylinder liners from the bottom to the top. Near the top of the cylinder liners, the water jacket is made smaller. The smaller area is the area that has the hottest temperature. This shelf (smaller area) causes the coolant to flow faster for better liner cooling. Coolant from the top of the liners flows into the cylinder head which sends the coolant around the parts that have the hottest temperature. Coolant flows to the top of the cylinder head (one at each cylinder). The coolant flows out of the cylinder head through an elbow into a water manifold (5). Coolant then flows through the manifold to the temperature regulator housing (thermostat).Water temperature regulator housing (6) has an upper flow section and a lower flow section. The regulator housing uses four temperature regulators. The sensing bulbs of the four temperature regulators are in the coolant in the lower section of the housing. Before the regulators open, cold coolant is sent through the bypass line back to the inlet of the water pump. The coolant flow in the bypass line is restricted when the temperature of the coolant increases enough to open the regulators. When the regulators open, coolant is circulated through the outlets back to the radiator or to the heat exchanger (9).