1. Automobile Engine NO.4

2. NO.1

3. Mercedes-Benz E-class

4. The Cooling System How the colling system works

5. How the cooling system works The main parts of the engine cooling system are radiator, pressure cap, hoses, thermostat, coolant pump, fan, and drive belt (except on electric engines). The system is filled with coolant, which should be a 50-50 mixture of antifreeze and water. No matter where you live or how hot or cold the weather becomes, the mixture should maintained the year around (As shown in Fig.) The water pump and engine cooling fan are mounted on the same shaft and driven by a belt connected to the engine. The pump draws coolant from the bottom of the radiator and forces it through passages surrounding the hot area-the cylinders, combustion chambers, valves and spark plugs. From there the coolant flows through a hose into the top of the radiator, then downward through tubes attached to cooling fins and surrounded by air passages (As shown in Fig) Heat is transferred from the coolant to air forced through the radiator passages by the fan and the forward motion of the vehicle. PICTORIAL (1)PICTORIAL (2)

7. Cooling Passages Coolant pump Lower Radiator hose Fan Thermostat Upper Radiator hose Core Drive belt Radiator Tanks The cooling system