ROD - TORQUE 1838600 - Caterpillar

Jacket Water
Illustration 1 g00290887
Cooling system schematic
(1) Cylinder block
(2) Engine oil cooler
(3) Regulator housing
(4) Jacket water pump
(5) Radiator
(6) Bearing housing for the turbocharger
(7) Power train oil cooler
(8) Brake oil cooler Coolant flows into jacket water pump (4) through an elbow. The elbow is connected to the source of jacket water coolant (5). The coolant flow splits and part of the coolant is sent through engine oil cooler (2).The coolant flows upward through the water jackets. The coolant flows around the cylinder liners from the bottom to the top. The water jacket is smaller near the top of the cylinder liners. The hottest temperature is 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 the cylinder head which sends the coolant around the parts which have the hottest temperature. Coolant then goes to the top of the cylinder head. Coolant flows through an elbow. Coolant enters a water manifold at each bank of cylinders. Coolant goes through the manifold to regulator housing (3).Regulator housing (3) 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. This coolant is sent back to the inlet of jacket water pump (4). As the temperature of the coolant increases, the regulators start to open and coolant flow in the bypass line is restricted. All coolant is sent through the outlets to jacket water coolant (5). Also, coolant flows from the upper regulator housing (3) to the bearing housing for the turbocharger (6). The coolant is then returned to radiator (5).Separate Circuit Aftercooler (SCAC)
Illustration 2 g00290885
SCAC cooling system
(8) Brake oil cooler
(9) Auxiliary pump
(10) Aftercooler
(11) SCAC coolant source (radiator) In the SCAC cooling system, the coolant flows from SCAC coolant source (radiator) (11) to auxiliary pump (9). The auxiliary pump sends the coolant to aftercooler (10). From the aftercooler, the coolant flows to brake oil cooler (8). From the brake oil cooler, the coolant flows back to SCAC coolant source (radiator) (11).