TM2361 (24JUN08) 9010-05-8 450DLC Excavator Operation and Tests 062608 PN=256 Theory of Operation Engine Cooling System Operation 9010 05 8 –UN–17DEC05 TX1001522 1—Primary EGR Cooler 3—Cylinder Head 5—Coolant Pump 8—Radiator 2—Secondary EGR Cooler 4—Oil Cooler 6—Thermostat (2 used) 9—Cooling Fan The main parts of the cooling system consist of the provides even heat distribution during rapid engine radiator (8), coolant pump (5), coolant inlet and outlet warmup. As the temperature of the engine coolant pipes, and dual thermostats (6).
The system is a increases to 82°C (180°F), dual thermostats close the compulsory water circulating system, pressured by a top-bypass and open the normal flow which, directs gear-driven centrifugal coolant pump and regulated by coolant to the radiator (8). As the coolant flows down dual top-bypass type thermostats. At initial start-up, through the radiator, excess heat is drawn away by the coolant is circulated from the water pump inlet through cooling fan (9). The low temperature coolant is then the coolant pump , oil cooler (4), cylinder head (3), returned to the coolant pump inlet and the flow cycle is primary EGR cooler (1), secondary EGR cooler (2) and complete.
back through dual top-bypass thermostats. This JC89288,000003D –19–24JAN06–1/1