LINK-DRIVE 3G3702 - Caterpillar

Illustration 1 g03506240
Cooling system (1) Radiator. (2) Aftercooler. (3) Jacket water pump. (4) Cooler for power train (Torque converter and transmission). (5) Bypass tube. (6) Engine oil cooler. (7) Cylinder head. (8) Water regulator. (AA) Regulated coolant. (BB) Unrestricted coolant.The radiator (1) is mounted at the rear center of the machine. With the engine at operating temperature, the jacket water pump (3) draws coolant from the bottom of the radiator. From the jacket water pump, coolant flows through a passage in the front timing gear cover and into the front of the cylinder block (11). Some of the coolant flows through the internal engine oil cooler (6) and then into the cylinder block. Coolant in the cylinder block flows through the block, around the cylinders, and then upward into the cylinder head (7). From the cylinder head, the coolant flows forward to the water temperature regulator (thermostat) (8). With the engine at operating temperature, the thermostat is OPEN, allowing the heated coolant to flow directly to the top of the radiator. As the coolant flows downward through the radiator, ambient air drawn through the radiator core by the fan cools the flow of coolant. The cooled coolant is again drawn from the radiator and is recirculated through the engine by the jacket water pump. When the engine is cold, the thermostat is CLOSED and the coolant flows directly to the jacket water pump inlet through a bypass tube (5). As the temperature of the coolant increases, the thermostat opens, closing off the bypass tube. The coolant then begins to flow to the radiator. When the thermostat opens further, more coolant flows to the radiator. The water temperature regulator housing for the C7.1 ACERT Tier 3 engine contains only one thermostat.Radiator Assembly
Illustration 2 g03506474
Radiator (Rear View) (1) Radiator. (2) Aftercooler. (9) Hydraulic Oil Cooler.Radiator assembly (1) is the source of coolant for the cooling system. The radiator is made up of the following three sections: radiator top tank, radiator bottom tank and radiator core assembly. Also, radiator assembly (1) includes air aftercooler (2) and hydraulic oil cooler (9) .ReferenceFor additional information about cooling the hydraulic system, refer to the Service Manual module Systems Operation, "Hydraulic Fan System" for the machine that is being serviced.The radiator top tank accepts the return coolant from the water regulator housing. The coolant flows from the radiator top tank down the tubes of the radiator core. Then, the coolant flows into the bottom tank. As the coolant flows through the radiator core and the air is pulled around the radiator core, the temperature of the coolant is reduced.Air to Air Aftercooler
Illustration 3 g03506524
Air to Air Aftercooler (2) Aftercooler. (9) Muffler. (10) Air cleaner. (11) Turbocharger. (12) Cooled air enters the air intake manifold on right side of machine. (CC) Inlet air. (DD) Exhaust gases.The air-to-air aftercooler system (ATAAC system) provides cooled air to air intake manifold (12) on the right side of the machine. Air is drawn in through air cleaner (10) and into turbocharger (11). The