NUT 1B2578 - Caterpillar

Illustration 1 g01344609
(1) Water manifold
(2) Tube to water cooled turbocharger and exhaust manifold
(3) Aftercooler
(4) Expansion tank
(5) Cylinder head
(6) Cylinder block
(7) Oil cooler
(8) Tube to aftercooler
(9) Water pump
(10) Tube to water pump
Illustration 2 g01344614
View A-A
(11) Tube to expansion tank
(12) Water temperature regulator housing
(13) Inlet from heat exchanger
(14) Outlet to heat exchanger Coolant goes into water pump (9) through elbow (10). The elbow connects to expansion tank (4). The coolant flow is divided at the outlet of the water pump. Part of the coolant flow is sent to aftercooler (2) through tube (8). The remainder of the coolant goes through engine oil cooler (7).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.Coolant that is sent to the aftercooler goes through the aftercooler core. The coolant is sent by an elbow into a passage in cylinder block (6). The passage is near the center of the vee at the rear of the cylinder block. The coolant flows through the engine oil cooler into the water jacket of the cylinder block at the right rear cylinder. The coolant goes to both sides of the cylinder 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. The hottest temperature is near the top of the cylinder liners. The water jacket is smaller near the top of the cylinder liners. This shelf causes the coolant to flow faster for better liner cooling. Coolant from the top of the liners goes into cylinder head (5). The cylinder head sends the coolant around the hottest parts. Coolant then goes to the top of the cylinder head. The coolant goes out through an elbow at each cylinder head and into water manifold (1) at each bank of cylinders. Coolant goes through the water manifold to water temperature regulator housing (12).The water temperature regulator housing has an upper flow and a lower flow section. The water temperature 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 water temperature regulators open, coolant is sent through tube (11) back to the expansion tank. As the temperature of the coolant increases and the water temperature regulators start to open, the coolant flow in the bypass tube is restricted. Most of the coolant is sent through the outlet to the heat exchanger.The total system capacity will depend on the amount of coolant in the cylinder block as well as the amount of coolant in the heat exchanger.