| Cooling system | |
| General parameters | |
| Cooling system type | Closed, with water pump, thermostat, radiator, fan (electric or with viscous clutch) and a separately installed expansion tank |
| System volume | See Specifications for Chapter Routine care and maintenance |
| Coolant composition (proportion of antifreeze in the coolant to ensure frost resistance) | |
| up to -37°C | 50% |
| up to -45°C | 55% |
| Pressure in the system | About 1.4 bar (the exact value is indicated on the expansion tank cap). |
| Thermostat | |
| Valve stroke, mm | not less than 8 |
| Valve activation temperatures,°C | |
| Start of opening | 85÷89 |
| Full opening | 102 |
| Cooling system tract cover | |
| Petrol models | On petrol models, the cooling system cover is not subject to testing and must be replaced if it fails |
| Diesel models (lid code 140/200) | |
| Vacuum valve response depth, bar | 0.1 |
| Opening pressure of safety valve, bar | |
| First stage (coolant temperature 130/134°C) | 1.4 |
| Second stage (coolant temperature 137/143°C) | 2.0 |
| Lid test pressure, bar | 1.4 (the lid must hold this pressure for at least 2 minutes) |
| Air conditioning system | |
| Refrigerant type | R134a |
| Volume of refrigerant, g | 750 |
| Type of refrigeration oil | Synthetic PAG |
| The amount of compressor oil added when: | |
| Replacement of evaporator, cm³ | 40 |
| Replacement of capacitor, cm³ | 20 |
| Replacement of receiver-dryer, cm³ | 10 |
| Replacement of suction line, cm³ | 20 |
| Replacement of pressure line, cm³ | 20 |
| Compressor replacement, cm³ | 20 |
| Leak detection, cm³ | 20 |
| After a sudden emptying of the system, cm³ | 40 |
| Tightening force of threaded connections, Nm | |
| Cooling system | |
| M111 | |
Thermostat housing mounting bolts | |
| 10 |
| 25 |
| ATF Cooling Line Union Nut on Radiator (models with AT) | 20 |
| Hollow bolt of nipple connection | 20 |
| Bolt for fastening the fan impeller to the viscous coupling | 10 |
| Bolt for fastening the viscous coupling to the bearing housing (tightened using a special device) | 40 |
| Water pump mounting bolts to engine crankcase | |
| M6 | 10 |
| M8 | 25 |
| Water pump pulley mounting bolt | 10 |
| M112/113 | |
| Thermostat housing mounting bolts (M6) | 10 |
| ATF Cooling Line Union Nut on Radiator | 20 |
| Hollow bolt of the nipple connection on the radiator (M12x1.5) | 30 |
| Bolt for fastening the fan impeller to the viscous coupling | 10 |
| Bolt for fastening the viscous coupling to the bearing housing (tightened using a special device) | 40 |
| Generator mounting screws | 42 |
| Bolts for fastening the damper of the auxiliary drive belt tensioner | |
| To the tensioner | 25 |
| To the water pump | 35 |
| Self-tapping bolts for fastening the water pump to the timing cover | |
| M6 | |
| 14 |
| 10 |
| M8 | |
| 35 |
| 25 |
| Water pump pulley mounting bolt | 10 |
| M612 | |
| Cylinder Head Cover Trim Panel Fastening Screws | 10 |
| Air Distributor Trim Panel Fastening Screws | 10 |
| Thermostat housing mounting bolts (M6) | 9 |
| Hollow bolt of the nipple connection on the radiator (oil leak line) | 30 |
| Bolts securing the water pump to the timing belt cover | |
| M6 | 14 |
| M8 | 20 |
| Water pump pulley mounting bolt | 35 |
| M628 | |
| Thermostat housing mounting bolts (M6) | 9 |
| ATF Cooling Line Union Nut on Oil Cooler | 25 |
| Hollow bolt of the ATF cooling line union on the oil cooler | 25 |
| Hollow bolt of the nipple connection on the radiator (oil leak line) | 30 |
| Water pump mounting bolts to engine crankcase | 10 |
| Water pump pulley mounting bolt | 25 |
| Heating/Ventilation/Air Conditioning Systems | |
| Nuts securing the instrument panel to the engine compartment bulkhead | 8 |
| Bolts securing the instrument panel to the A-pillars | 19 |
| Instrument cluster to transmission tunnel mounting bolts | 30 |
| Union nut for fastening the tube to the expansion valve of the K/V system | 10 |
| Refrigerant line to receiver mounting bolt | 10 |
| Refrigerant line to condenser mounting bolt | 20 |
| Bolt for fastening the expansion valve to the evaporator heat exchanger | 10 |
Engine cooling system
All models of the vehicles considered in this Manual are equipped with a positive pressure engine cooling system with thermostatic control of the working fluid circulation. The water pump is fixed to the engine block and pumps the coolant through the cooling tract of the latter. The flow of liquid washes the areas of each cylinder in the block, after which it is directed to the rear of the engine. Cooling channels laid in the block and cylinder head castings provide intensive cooling of the intake and exhaust ports, spark plug installation areas and exhaust valve guides.
From the moment the engine is started, the cooling system goes through three operating modes: at the first stage, until the coolant temperature rises above a certain value, it circulates in a small circle from the working circuit of which the radiator is excluded. As the liquid heats up further, the plate valve of the wax-filled thermostat entering the system tract opens and the radiator is connected to the circulation circuit. Then, when the coolant temperature reaches the next control value, a temperature-sensitive switch is triggered, activating the cooling system fan, the additional air flow pumped by it significantly increases the efficiency of the radiator heat exchanger.
The cooling system has a sealed design and is tightly closed with a radiator cap capable of withstanding a certain excess pressure, which increases the boiling point of the coolant and, accordingly, the efficiency of heat removal through the radiator. When the internal pressure in the system exceeds a certain value, excess coolant flows through the connecting (overflow) tube into the expansion tank. As the system cools, the liquid automatically returns from the tank to the radiator.
Filling the system with coolant is done through the neck of the expansion tank (see Chapter Checking the cooling system and frost resistance of the coolant, replacing the liquid), which simultaneously also acts as a receiver, accumulating the excess liquid displaced from the radiator.
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Due to the listed design features, such a cooling system is called closed, since it excludes any functional losses of working heat.
Heating and ventilation system
The heating system consists of fans and heat exchangers located in the front and rear sections of the passenger compartment. Hot coolant passes through the heat exchangers. When the heater control handle located on the control panel is moved, the valves open and hot air begins to flow into the passenger compartment. If you turn on the heater fan, air will be forced into the passenger compartment.
The outside air is passed through a special filter before entering the cabin, and the majority of dust particles settle in the carburetor. The cabin filter should be replaced on a regular basis in accordance with the Schedule of routine vehicle maintenance (see Chapter Schedule of current maintenance). Violation of the filter permeability leads to a decrease in the performance of the heating/ventilation/air conditioning systems.
Distribution of air flows of the ventilation system is carried out by means of dampers. It is possible to switch the air circulation modes. The dampers are driven by servomotors.
Air conditioning system
See Section General information and safety precautions.