Cooling system - liquid closed type with forced circulation of liquid, with expansion tank 2 (figure 31). It consists of a coolant pump 16, a non-separable thermostat 25, an electric fan, a radiator with an expansion tank 2, pipelines, hoses, drain plugs and cooling jackets for the cylinder block and the cylinder head. The pump is rotated by a toothed belt 17 of the camshaft drive.
Figure 31. Cooling system:
1 - expansion tank cap; 2 - expansion tank; 3 - radiator supply hose; 4 - hose from the radiator to the expansion tank; 5 - radiator drain hose; 6 - left radiator tank; 7 - radiator tubes; 8 - electric fan switch sensor; 9 - right radiator tank; 10 - drain plug; 11 - radiator core; 12 - Electric fan casing; 13 - Electric fan impeller; 14 - Electric motor; 15 - toothed pump pulley; 16 - Coolant pump; 17 - toothed belt; 18 - heater radiator outlet pipe; 19 - pump supply pipe; 20 - hose for draining liquid from the intake manifold heater to the carburetor heater unit; 21 carburetor heating block; 22 - outlet pipe; 23 - supply pipe to the heater radiator; 24 - hose for draining liquid from the intake manifold heater and the carburetor heater unit; 25 - thermostat; 26 - hose from the expansion tank to the thermostat.
The cooling system is filled with Tosol A-40M liquid, which does not freeze to a temperature of minus 40°C and prevents scale formation in the system. The liquid is an ethylene glycol mixture with anti-corrosion and anti-foaming additives. The density of the Tosol A-40M coolant is 1.078...1.085 g/cm³. If it is necessary to lower the freezing temperature, Tosol-AM or Tosol-A liquids are used, the addition of which increases the density of the liquid and lowers the freezing temperature.
The capacity of the system, including the interior heater, is 7.8 l. The fluid level in the system should be 25...30 mm above the "MIN" mark on the translucent expansion tank 2, allowing visual control of the level. The check is performed on a cold engine. If necessary, add fluid to the expansion tank.
The temperature of the liquid in the cooling system of a warmed-up engine at an ambient temperature of 20...30°C with a full load and when driving at a speed of 90 km/h should not exceed 95°C. To control the temperature, there is a sensor that is screwed into the cooling jacket of the cylinder head. The liquid temperature gauge is installed on the instrument cluster in the passenger compartment.
When the engine is running, the heated liquid flows through the outlet pipe 22 through the hose 3 into the radiator for cooling or into the thermostat 25, depending on the position of the valves of the latter. Then the coolant is directed by the pump 16 into the engine cooling jacket. The liquid circulates through the hoses 20 and 24, heating the combustible mixture in the intake manifold and heating the throttle zone of the first chamber of the carburetor.
The car's interior heater radiator is connected to the cooling system via pipes 18 and 23 using hoses.