Engine cooling system - liquid, closed type, with forced circulation of coolant

The main elements of the system are a water pump, a radiator, thermostats, a fan, a fan drive fluid coupling, a fluid coupling switch, an expansion tank, bypass pipes, blinds.

1 - Protective tube, 2 - Brake lever, 3 - Brake actuator mounting bracket, 4 - Radiator brake tension frame, 5 - Brake carrier, 6 - Radiator brake plates, 7 - Louvre drive rod, 8 - Louvre control rod radiator, 9 - Fan impeller, 10 - Radiator, 11 - Cooling system drain valve; 12 - Supply pipe of the right semi-block; 13 - Branch pipe of the supply pipe; 14 - Fan drive hydraulic clutch switch; 15 - Cylinder head; 16 - Drain cock handle; 17 - Thermostat box; 18. Branch pipe for draining coolant from the expansion tank to the water pump; 19 - Branch pipe for draining coolant to the heater; 20 - Coolant level control valve; 21- Expansion tank; 22 - Steam-air plug; 23 - Bypass pipe from the radiator to the expansion tank; 24 - Connecting tube from the compressor to the expansion tank; 25. Compressor; 26 - Right drainage pipe; 27 - Connecting water pipe; 28 - Left water collection pipe; 29 - Bypass pipe from thermostats; 30 - Water pump; 31, 32 - Thermostat valves; 33 - Elbow outlet pipe; 34 - Plug body; 35 - Valve rack; 36 - Spring; 37 - Cover spring; 38 - Exhaust valve (58-80 kPa) (0.58-0.8kgf / cm 2); 39 - Exhaust valve; 40 - Gasket

During engine operation, the circulation of coolant in the system is created by a centrifugal pump.

Fluid from the pump is injected into the water cavity of the left row of cylinders, and through a pipe - into the water cavity of the right row of cylinders.

Washing the outer surfaces of the cylinder liners, the coolant through the holes in the upper attachment planes of the cylinder block enters the water cavities of the cylinder heads.

From the cylinder heads, hot liquid flows through the catchment pipes and enters the thermostat box, from which, depending on the temperature, it is sent to the radiator or to the water pump inlet.

The temperature of the coolant in the system is maintained within 80...98 °C.

The thermal regime of the engine is provided automatically by thermostats and a switch for the hydraulic clutch of the fan drive, which change the direction of the fluid flow and the fan operation mode depending on the temperature of the coolant in the engine cooling system.