Engine cooling system parts
1. Radiator; 2. Expansion tank; 3. Drain plug; 4. Thermostat housing; 5. Thermostat; 6. Thermostat gasket; 7. Water pump; 8. Water pump gasket; 9. Pulley; 10. Viscous fan clutch; 11. Fan; 12. Heater outlet pipe; 13. Coolant temperature sensor; 14. Radiator drain hose
The car uses a closed-type liquid cooling system with forced circulation of liquid using a centrifugal pump (see figure Engine cooling system parts). It includes a radiator, water pump, thermostat, atmospheric expansion tank and a viscous fan. The 4D56T engines use an electric fan with a plastic impeller mounted on the electric motor shaft, which is switched on and off using the electric fan switch.
The tubular-fin radiator operates under high pressure.
Opening pressure of the filler cap valves, kgf/cm²:
- exhaust valve: 0.75–1.05 (greater than or equal to 0.65)*;
- intake valve: less than or equal to 0.05.
Note: Since May 1991, a one-piece fan guide casing has been installed, which has increased the cooling capacity of the radiator.
The thermostat housing is attached directly to the water pump housing.
Opening temperature of the main thermostat valve: 76.5°C.
Attention! On 4D56T engines, the main thermostat valve begins to open at a temperature of 82°C and opens completely at a temperature of 95°C.
The vane type centrifugal water pump is driven by a V-belt together with the generator. The fan is mounted on the water pump axle via a viscous coupling.
Please note! On 4D56 engines produced since May 1991, the water pump performance has been increased due to a change in the pump design on the suction side.
Water pump drive belt Mitsubishi MD159551.
The normal deflection of the belt when pressing with a force of 10.0 kgf on the middle of the branch between the generator pulley and the water pump pulley should be within 10–13 mm.