Engine cooling VAZ 2104, 2105, 2107

Cooling of the engine VAZ 2104, 2105, 2107: 1. A pipe for draining fluid from the heater radiator to the coolant pump; 2. Hose for removing the coolant from the inlet pipe; 3. Hose for removing coolant from the heater radiator; 4. Hose for supplying fluid to the heater radiator; 5. Thermostat bypass hose; 6. Outlet branch pipe of the cooling jacket; 7. Radiator supply hose; 8. Expansion tank; 9. Tank cap; 10. Hose from the radiator to the expansion tank; 11. Radiator cap; 12. Plug outlet valve; 13. Inlet valve; 14. Upper radiator tank; 15. Filler neck of the radiator; 16. Radiator tube; 17. Radiator cooling plates; 18. Fan casing; 19. Electric fan; 20. Pulley for the drive of the coolant pump; 21. Rubber mount; 22. Window on the side of the cylinder block for supplying coolant; 23. Oil seal holder; 24. Coolant pump roller bearing; 25. Pump cover; 26. Hub of the pump drive pulley; 27. Pump roller; 28. Locking screw; 29. Oil seal collar; 30. Pump casing; 31. Pump impeller; 32. Pump inlet pipe; 33. Lower radiator tank; 34. Outlet radiator hose; 35. Coolant pump drive belt; 36. Coolant pump; 37. Hose for supplying coolant to the pump; 38. Thermostat; 39. Rubber insert; 40. Inlet pipe (from the radiator); 41. Main valve; 42. Bypass valve; 43. Thermostat housing; 44. Branch pipe of the bypass hose; 45. Branch pipe of a hose for supplying coolant to the pump; 46. ​​Thermostat cover; 47. Piston of the working element; 48. I. Scheme of thermostat operation; 49. II. The temperature of the liquid is less than 80 C; 50. III. Liquid temperature 80 - 94 С; 51. IV. The liquid temperature is more than 94 C. The engine cooling system is liquid, closed type, with forced circulation of liquid. The system capacity is 9.85 liters, including the heating system for the passenger compartment. The cooling system consists of the following elements: a coolant pump 36, a radiator, an expansion tank 8, pipelines and hoses, an electric fan 19, block cooling jackets and a cylinder head.

When the engine is running, the liquid heated in the cooling jackets enters through the outlet 6 through hoses 5 and 7 into the radiator or thermostat, depending on the position of the thermostat valves. Next, the coolant is sucked in by the pump 36 and supplied again to the cooling jacket. The engine cooling system is liquid, closed type, with forced circulation of liquid. The system capacity is 9.85 liters, including the heating system for the passenger compartment. The cooling system consists of the following elements: a coolant pump 36, a radiator, an expansion tank 8, pipes and hoses, a fan 19, block cooling jackets and a cylinder head.

When the engine is running, the liquid heated in the cooling jackets enters through the outlet 6 through hoses 5 and 7 into the radiator or thermostat, depending on the position of the thermostat valves. Next, the coolant is sucked in by the pump 36 and supplied again to the cooling jacket. Checking the coolant level is carried out on a cold engine (at a temperature of plus 15-20 C) by the level of the liquid in the expansion tank 8, which should be 3-4 mm above the "MIN" mark. To monitor the coolant temperature, there is a sensor installed in the cylinder head and an indicator on the instrument panel.

Under normal temperature conditions of engine operation, the pointer arrow is at the beginning of the red field of the scale within 80-100 C. The transition of the arrow to the red zone indicates an increased thermal regime of the engine, which may be caused by malfunctions in the cooling system (weakening of the pump drive belt, insufficient cooling liquid, thermostat or electric fan malfunction), as well as difficult road conditions.

The fluid from the system is drained through the drain holes closed with plugs: one is in the left corner of the lower radiator tank 33, the other is in the cylinder block to the left in the direction of the vehicle. The car's interior heater is connected to the cooling system. The heated fluid from the cylinder head flows through hose 4 through the tap into the heater radiator, and is sucked off by pump 36 through hose 3 and pipe 1.

The coolant pump is a centrifugal type, driven from the crankshaft pulley by a V-belt to drive the generator. The pump is attached to the cylinder block on the right side through a gasket. The body 30 and cover 25 of the pump are cast from an aluminum alloy. A roller 27 is installed in the bearing cover 24, which is locked by a screw 28. The bearing 24 is two-row, non-separable, without an inner cage. The bearing is filled with grease during assembly and is not relubricated. On the roller 27, on the one hand, the impeller 31 is pressed, and on the other, the hub 26 of the pump drive pulley.

The end of the impeller, in contact with the sealing ring, is hardened by high frequency currents to a depth of 3 mm. The O-ring is pressed against the impeller by a spring through a rubber cuff 29. The oil seal is non-separable, consists of an outer brass cage 23, a rubber cuff and a spring. It is pressed into the pump cover 25. The pump housing has an inlet 32 ​​and a window 22 towards the cylinder block for pumping coolant. With normal tension of the pump drive belt, its deflection under a force of 10 kgf should be within 10-15 mm.

Electric fan. The fan is four-bladed, made of plastic. The fan blades have a radially variable installation angle and, to reduce noise, a variable step along the hub. The fan is installed on the motor shaft and pressed with a nut. For better efficiency, the fan is housed in a casing 18, which is bolted to the radiator brackets. The electric motor assembly with the fan is installed on three rubber bushings and is fastened with nuts to the studs of the fan casing 18. The switching on and off of the electric fan 19 is carried out automatically depending on the temperature of the liquid using a sensor of the TM-108 type installed in the lower radiator tank on the left side. The closing temperature of the sensor contacts should be in the range of 89-95 C, and the opening temperature in the range of 84-90 C.

Radiator. A radiator with upper and lower tanks, with two rows of vertical brass pipes and tin-plated cooling plates, is fastened with four bolts to the front of the body and rests on rubber supports 21. The filler neck 15 of the radiator is closed with a stopper AND and is connected with a hose 10 with a translucent plastic expansion tank 8. Radiator stopper has an inlet valve 13 and an outlet valve 12, through which the radiator is connected with a hose to the expansion tank.

The inlet valve is not pressed against the gasket (clearance 0.5-1.1 mm) and allows the inlet and outlet of coolant to the expansion tank when the engine is heated and cooled. Since 1988, vehicles have been fitted with radiators with an aluminum core and plastic tanks. Thermostat and cooling system operation. The cooling system thermostat accelerates engine warm-up and maintains the required engine thermal mode. Under optimal thermal conditions, the coolant temperature should be 85 - 95 C. Thermostat 38 consists of a body 43 and a cover 46, which are seamed together with the seat of the main valve 41.

The thermostat has an inlet pipe 40 for inlet of cooled liquid from the radiator, a pipe pipe 44 of the bypass hose 5 for bypassing fluid from the cylinder head to the thermostat and a pipe pipe 45 for supplying coolant to the pump 36. The main valve is installed in a thermoelement cup, in which a rubber insert 39 is rolled. The rubber insert contains a polished steel piston 47, which is fixed to a stationary holder. A thermosensitive solid filler is placed between the walls and the rubber insert. The main valve 41 is pressed against the seat by a spring. On the valve there are two posts, on which a bypass valve 42 is installed, which is biased by a spring.

The operation of the internal combustion engine of any car is associated with high temperatures. The internal combustion engine heats up during the combustion of the fuel-air mixture in the cylinders and as a result of the friction of its elements. The cooling system helps to avoid overheating of the power unit.

General characteristics of the cooling system VAZ 2107

The VAZ 2107 engine of all models has a sealed liquid cooling system with forced circulation of the coolant (coolant).

Purpose of the cooling system

The cooling system is designed to maintain the optimum temperature of the power unit during its operation and timely and controlled removal of excess heat from the heating units. Individual elements of the system are used to heat the passenger compartment during the cold season.

Cooling system parameters

The cooling system of the VAZ 2107 has a number of parameters that affect the operation and performance of the power unit, the main of which are:

• the amount of coolant - regardless of the fuel supply method (carburetor or injection) and engine size, the same cooling system is used on all VAZ 2107. According to the manufacturer's requirements, 9.85 liters of refrigerant is required for its operation (including heating the passenger compartment). Therefore, when replacing antifreeze, you should immediately purchase a ten-liter container;
• engine operating temperature - The engine operating temperature depends on its type and volume, the type of fuel used, the number of crankshaft revolutions, etc. For the VAZ 2107, it is usually 80–95 0 C. The engine heats up to operating condition, depending on the ambient temperature within 4-7 minutes. In case of deviation from these values, it is recommended to immediately diagnose the cooling system;
• working pressure of the coolant - Since the cooling system of the VAZ 2107 is sealed, and the antifreeze expands when heated, a pressure that exceeds atmospheric pressure is created inside the system. This is necessary to raise the boiling point of the coolant. So, if under normal conditions water boils at 100 0 C, then with an increase in pressure to 2 atm, the boiling point rises to 120 0 C. In a VAZ 2107 engine, the operating pressure is 1.2–1.5 atm. Thus, if the boiling point of modern coolants at atmospheric pressure is 120–130 0 C, then under operating conditions it will increase to 140–145 0 C.

The device of the cooling system VAZ 2107

The main components of the VAZ 2107 cooling system include:

• water pump (pump);
• main radiator;
• main radiator fan;
• interior heater (stove) radiator;
• stove tap;
• thermostat (thermostat);
• expansion tank;
• coolant temperature sensor;
• coolant temperature sensor pointer;
• control temperature sensor (only in injection engines);
• fan switch sensor (only in carburetor engines);
• connecting pipes.

This should also include the engine cooling jacket - a system of special channels in the cylinder block and the block head through which coolant circulates.

Video: design and operation of the engine cooling system

Water pump (pump)

The pump is designed to provide continuous forced circulation of coolant through the engine cooling jacket during engine operation. It is a conventional centrifugal pump that pumps antifreeze into the cooling system using an impeller. The pump is located on the front of the cylinder block and is driven by the crankshaft pulley through a V-belt.

Pump design

The pump consists of:

How the pump works

The principle of operation of a water pump is quite simple. When the crankshaft rotates, the belt drives the pump pulley, transmitting torque to the impeller. The latter, rotating, creates a certain coolant pressure inside the housing, forcing it to circulate inside the system. The bearing is designed for uniform rotation of the shaft and reducing friction, and the oil seal ensures the tightness of the device.

Pump malfunctions

The pump resource for the VAZ 2107 regulated by the manufacturer is 50-60 thousand kilometers. However, this resource may decrease in the following situations:

• use of low-quality coolant or water;
• ingress of dirt, impurities, foreign objects into the cooling system;
• excessive tension on the drive belt.

The result of the influence of these factors are:

• impeller wear;
• wear or damage to the stuffing box;
• misalignment of the pump shaft with subsequent wear of the bearing and possible jamming of the device.

When such malfunctions are detected.

Main radiator

The radiator is designed to cool the coolant entering it due to heat exchange with the environment. This is achieved due to the peculiarities of its design. The radiator is mounted in the front of the engine compartment on two rubber cushions and is attached to the body with two studs and nuts.

Radiator design

The radiator consists of two vertically positioned tanks and pipes connecting them. Thin plates (lamellas) accelerating the heat transfer process are located on the tubes. One of the tanks is equipped with a filler neck with a sealed plug. The neck has a valve and is connected to the expansion tank with a thin rubber hose. In carburetor VAZ 2107 engines, a seat is provided in the radiator for a sensor for turning on the cooling system fan. There is no such socket in models with injection engines.

The principle of the radiator

Cooling can be carried out both naturally and forcibly. In the first case, the coolant temperature is reduced by blowing the radiator with an oncoming air flow while driving. In the second case, the air flow is created by a fan attached directly to the radiator.

Radiator malfunctions

Failure of a radiator is most often associated with a loss of tightness as a result of mechanical damage or corrosion of pipes. In addition, the pipes can become clogged with dirt, deposits and impurities in the antifreeze, and the circulation of the coolant will be disrupted.

If a leak is found, you can try to solder the damaged area with a powerful soldering iron using a special flux and solder. Clogged tubing can be removed by flushing with reactive chemicals. As such substances, solutions of phosphoric or citric acid are used, as well as some household products for cleaning sewers.

Cooling fan

The fan is designed for forced blowing of the radiator. It turns on automatically when the coolant temperature rises to a certain value. In VAZ 2107 carburetor engines, a special sensor installed in the main radiator is responsible for turning on the fan. In injection power units, its operation is controlled by an electronic controller, based on the readings of a temperature sensor. The fan is fixed to the main radiator casing with a special bracket.

Fan design

The fan is a conventional DC motor with a plastic impeller mounted on the rotor. It is the impeller that creates the air flow and directs it to the radiator fins.

The voltage to power the fan is supplied from the generator through a relay and a fuse.

Fan malfunctions

The main fan faults include:

• broken wiring;
• failure of the relay;
• open or short circuit in the stator windings;
• wear of the collector brushes.

To check the functionality, the fan is connected directly to the battery.

Radiator and stove tap

The heater radiator is designed to heat the air entering the passenger compartment. In addition, the heating system of the passenger compartment includes a stove fan and dampers that regulate the direction and intensity of the air flow.

Stove radiator design

The stove radiator has the same design as the main heat exchanger. It consists of two reservoirs and connecting pipes through which the coolant flows. To accelerate heat transfer, the tubes have thin lamellas.

To stop the supply of warm air to the passenger compartment in summer, the stove radiator is equipped with a special tap that blocks the coolant circulation in the heating system. The crane is operated using a cable and a lever located on the front panel.

The principle of operation of the heater radiator

When the stove tap is open, hot coolant enters the radiator and heats the tubes with lamellas. The air currents passing through the radiator of the stove also heat up and enter the passenger compartment through the air duct system. When the tap is closed, coolant is not supplied to the radiator.

Malfunctions of the radiator and stove tap

The most common radiator and stove faucet breakdowns are:

• leakage caused by mechanical damage or corrosion;
• clogged radiator tubes;
• souring of the valve locking mechanism.

You can repair the stove radiator in the same ways as the main heat exchanger. If the crane malfunctions, it is replaced with a new one.

Thermostat

The thermostat maintains the required thermal mode of the engine and shortens the warm-up time at start-up. It is located to the left of the pump and is connected to it using a short pipe.

Thermostat design

The thermostat consists of:

The thermocouple is a sealed metal cylinder filled with special paraffin. Inside this cylinder is a stem that actuates the thermostat master valve. The body of the device has three fittings, to which the underwater hose from the pump, bypass and outlet nozzles are connected.

How the thermostat works

When the coolant temperature is below 80 0 C, the main thermostat valve is closed, and the bypass valve is open. In this case, the coolant moves in a small circle bypassing the main radiator. Antifreeze flows from the engine cooling jacket through a thermostat to the pump and then back into the engine. This is necessary in order for the motor to warm up faster.

When the coolant heats up to 80–82 0 C, the main thermostat valve starts to open. When the antifreeze heats up to 94 ° C, this valve opens completely, and the bypass valve, on the contrary, closes. In this case, the coolant moves from the engine to the cooling radiator, then to the pump and back to the cooling jacket.

Thermostat malfunctions

If the thermostat fails, the engine can both overheat and slower to warm up to operating temperature. This is the result of valve jamming. It is not difficult to check the operation of the thermostat. To do this, you need to start a cold engine, let it run for two or three minutes and touch your hand to the pipe that runs from the thermostat to the radiator. It must be cold. If the pipe is warm, then the main valve is constantly in the open position, which, in turn, will lead to a slow warm-up of the engine. Conversely, when the main valve blocks the flow of coolant to the radiator, the lower pipe will be hot and the upper pipe will be cold. As a result, the engine will overheat and the antifreeze will boil.

You can more accurately diagnose a thermostat malfunction by removing it from the engine and checking the behavior of the valves in hot water. To do this, it is placed in any heat-resistant container filled with water and heated by measuring the temperature with a thermometer. If the main valve starts to open at 80–82 0 C, and fully opens at 94 0 C, then the thermostat is working properly. Otherwise, the thermostat is out of order and needs to be replaced.

Expansion tank

Since antifreeze increases in volume when heated, the design of the VAZ 2107 cooling system provides for a special reservoir for accumulating excess coolant - an expansion tank (RB). It is located on the right side of the engine in the engine compartment and has a translucent plastic housing.

Tank design

RB is a plastic sealed container with a lid. To maintain the pressure in the tank close to atmospheric pressure, a rubber valve is installed in the lid. In the lower part of the RB there is a fitting to which a hose is connected from the neck of the main radiator.

On one of the walls of the reservoir there is a special scale for assessing the coolant level in the system.

The principle of the tank

When the coolant heats up and expands, overpressure builds up in the radiator. When it rises by 0.5 atm, the throat valve opens and the excess antifreeze begins to flow into the tank. There, the pressure is stabilized by a rubber valve in the cover.

Tank malfunctions

All RB malfunctions are associated with mechanical damage and subsequent depressurization or failure of the cover valve. In the first case, the entire tank is changed, and in the second, you can do with replacing the lid.

Temperature sensor and fan switch

In carburetor models VAZ 2107, the cooling system includes a sensor for a liquid temperature gauge and a sensor for turning on the fan. The first is installed in the cylinder block and is designed to control the temperature and transmit the information received to the dashboard. The fan switch is located at the bottom of the radiator and serves to supply power to the fan motor when the antifreeze reaches a temperature of 92 0 C.

The cooling system of injection engines also has two sensors. The functions of the first are similar to those of the temperature sensor of carburetor power units. The second sensor transmits data to the electronic control unit, which controls the on-off process of the radiator fan.

Sensor malfunctions and methods of their diagnostics

Most often, the sensors of the cooling system stop working normally due to problems with the wiring or due to the failure of their working (sensitive) element. You can check them for serviceability using a multimeter.

The operation of the fan activation sensor is based on the properties of the bimetal. When heated, the thermoelement changes its shape and closes the electrical circuit. As it cools, it returns to its normal position and stops the flow of electric current. To check, the sensor is placed in a container with water, after having connected the probes of the multimeter, which is turned on in the tester mode, to its terminals. Next, the container is heated by controlling the temperature. At 92 0 C, the circuit should close, which should be reported by the device. When the temperature drops to 87 0 C, a working sensor will open the circuit.

The temperature sensor has a slightly different principle of operation, based on the dependence of the resistance on the temperature of the medium in which the sensitive element is placed. The sensor test consists in measuring the resistance at a changing temperature. A working sensor at different temperatures should have different resistance:

• 20 0 C - 3.5 kOhm;
• 40 0 C - 1.5 kOhm;
• 60 0 C - 0.67 kOhm;
• 90 0 C - 0.25 kOhm.

To check, the temperature sensor is placed in a container with water, which gradually heats up, and its resistance is measured with a multimeter in ohmmeter mode.

Antifreeze temperature gauge

The coolant temperature gauge is located in the lower left side of the instrument cluster. It is a colored arc divided into three sectors: white, green and red. If the engine is cold, the arrow is in the white sector. When the engine warms up to operating temperature and subsequent operation in normal mode, the arrow moves to the green sector. If the arrow goes to the red sector, the engine is overheated. In this case, it is highly undesirable to continue driving.

Connecting pipes

The pipes are used to connect the individual elements of the cooling system and are ordinary rubber hoses with reinforced walls. Four pipes are used to cool the engine:

In addition, the cooling system includes the following connecting hoses:

• supply and removal of coolant from the heater radiator;
• drainage of liquid from the inlet pipeline;
• connections between the radiator neck and the expansion tank.

The pipes and hoses are fastened with clamps (spiral or worm gear). To remove or install them, it is enough to loosen or tighten the clamp mechanism with a screwdriver or pliers.

Coolant

As a coolant for the VAZ 2107, the manufacturer recommends using exclusively antifreeze. For the uninitiated car enthusiast, antifreeze and antifreeze are the same thing. Antifreeze is usually called all coolants without exception, regardless of where and when they are released. Antifreeze is a type of antifreeze produced in the USSR. The name is an abbreviation for “Separate Laboratory Organic Synthesis Technology”. All coolants, without exception, contain ethylene glycol and water. The only differences are in the type and amount of added anti-corrosion, anti-cavitation and antifoam additives. Therefore, for the VAZ 2107, the name of the coolant does not really matter.

The danger is posed by cheap low-quality coolants or outright fakes, which have recently become widespread and are often found on sale. The result of using such fluids can be not only radiator leakage, but also failure of the entire engine. Therefore, to cool the engine, you should buy coolant from proven and well-proven manufacturers.

Find out how to change the coolant yourself:

The possibilities of tuning the cooling system of the VAZ 2107

There are various ways to improve the efficiency of the VAZ 2107 cooling system. Someone installs a fan from Kalina or Priora on the radiator, someone is trying to warm up the interior better by supplementing the system with an electric pump from a Gazelle, and someone puts silicone pipes, believing that with them the engine will warm up faster and cool down. However, the feasibility of such tuning is highly questionable. The cooling system of the VAZ 2107 itself is pretty well thought out. If all its elements are in good working order, the engine will never overheat in summer, and in winter it will be warm in the cabin without turning on the stove fan. To do this, you only need to periodically pay attention to the maintenance of the system, namely:

• pour only high-quality coolant into the engine;
• change the coolant every 50 thousand km of run with a complete drain and flush of the system;
• monitor the coolant level and, if necessary, top up it;
• when refilling, in no case mix antifreeze with antifreeze;
• when replacing defective elements, use only quality certified parts.

Thus, the cooling system of the VAZ 2107 is quite reliable and simple. Nevertheless, it also needs periodic maintenance, which even an inexperienced car enthusiast can perform.

Parts of the carburetor engine cooling system: 1

- heater radiator; 2 - hose for draining the coolant from the heater radiator; 3 - hose for supplying coolant to the heater tap; 4 - a pipe for removing the coolant from the cylinder head; 5 - bypass hose; 6 - expansion tank; 7 - connecting hose of the expansion tank; 8 - hose for supplying coolant to the radiator; 9 - radiator plug; 10 - radiator electric fan; 11 - radiator of the cooling system; 12 - sensor for turning on the electric fan; 13 - hose for draining the coolant from the radiator; 14 - coolant pump; 15 - hose for supplying the coolant to the pump; 16 - thermostat; 17 - gauge for the coolant temperature gauge; 18 - hose for removing the coolant from the inlet pipeline; 19 - heater tap; 20 - a pipe for removing coolant from the heater radiator

The cooling system maintains optimal thermal conditions of the engine by controlled heat removal from the hottest parts. The engine cooling system is a liquid, sealed type, with forced circulation of the coolant and an expansion tank.

Connected to the cooling system interior heater radiator car. The heated coolant from the cylinder head flows through a hose through an open tap to the heater radiator, and then (through the fluid drain pipe) to the coolant pump.

The coolant pump is centrifugal, driven from the crankshaft pulley by a V-belt transmission. The pump consists of an aluminum alloy body and cover. The cover is secured with nuts to four studs screwed into the pump housing. A sealing gasket is installed between the body and the cover. The pump roller rotates in a double row sealed bearing. The flange of the pump drive pulley is pressed onto the front end of the roller, and a cast iron or plastic impeller is pressed onto the rear end.

Radiator - vertical, tubular-plate, with two plastic tanks and an aluminum core. The radiator is mounted on two rubber pads and is attached to the body with two bolts. The filler neck of the radiator is sealed with a plug and is connected with a hose expansion tank. The radiator plug has an outlet (steam) valve pressed by a spring against the seating collar of the filler neck, and an inlet valve through which the radiator is connected to the expansion tank. The inlet valve is not pressed against the seat and has a clearance of 0.5-1.1 mm, which allows the inlet and outlet of coolant to the expansion tank when heating or cooling. With a sharp increase in temperature or boiling of the liquid, the inlet valve does not have time to release the liquid into the expansion tank and closes, disconnecting the system from the expansion tank. When, due to further heating of the liquid, the pressure increases to 50 kPa, the outlet valve opens and part of the liquid begins to flow into the expansion tank. The expansion tank is closed with a plug with a rubber valve that maintains the pressure in the tank close to atmospheric.

The electric fan is installed behind the radiator. To reduce noise during operation, the fan impeller blades have a radially variable installation angle and pitch. The electric fan of the carburetor engine is turned on from a sensor screwed into the lower part of the right radiator tank. On cars of early production with constant forced ventilation, the fan switch and the electric fan were not installed. The fan impeller was attached to the coolant pump pulley and rotated constantly when the engine was running. On the injection engine, the electric fan is controlled by ECU commands (via a relay). The initial data for these commands is the signal from the coolant temperature sensor installed in the outlet pipe of the cooling system.

The cooling system thermostat serves to maintain the required thermal mode of the engine and accelerate its warming up. When the coolant temperature is below 80 ° C, the main thermostat valve is closed, and the bypass valve is open. The fluid circulates from the cooling jacket of the cylinder block through the thermostat bypass valve to the pump, which again supplies fluid to the cooling jacket, bypassing the radiator (small circle). This ensures that the engine warms up quickly. The temperature of the beginning of the opening of the main valve of the thermostat should be in the range of 80.6-81.5 ° C. The full stroke of the main valve must be at least 6 mm. When the liquid is heated above 94 ° C, the main thermostat valve opens completely, and the bypass valve closes. The fluid flows from the cooling jacket through the supply hose to the radiator. From the radiator, the liquid flows through the outlet hose through the main valve of the thermostat to the pump, which again supplies liquid to the cooling jacket (large circle). In the temperature range 80-94 ° C, the thermostat valves are in an intermediate position and the liquid circulates both in a small and a large circle. Regardless of the position of the thermostat valves, when the heater tap is open, the fluid always circulates through the heater radiator. In addition, fluid is constantly circulated through the intake manifold heater or throttle body (on an injection engine).

Parts of the cooling system of the injection engine

: 1 - heater radiator; 2 - hose for draining the coolant from the heater radiator; 3 - hose for supplying coolant to the heater tap; 4 - hose for removing the coolant from the throttle body heating unit; 5 - sensor (control system) of coolant temperature; 6 - hose for supplying coolant to the throttle body heating unit; 7 - expansion tank; 8 - hose for supplying coolant to the radiator; 9 - connecting hose of the expansion tank; 10 - radiator plug; 11 - radiator of the cooling system; 12 - radiator electric fan; 13 - hose for draining the coolant from the radiator; 14 - coolant pump; 15 - hose for supplying the coolant to the pump; 16 - thermostat; 17 - bypass hose; 18 - gauge for the coolant temperature gauge; 19 - a pipe for removing the coolant from the cylinder head; 20 - heater tap; 21 - a pipe for removing coolant from the heater radiator

VAZ 2104 with rear wheel drive and station wagon was produced from 1983 to 2012. The model was constantly improved: the electrical equipment was changed, a fuel injection system, a five-speed gearbox and semi-sports front seats appeared. The VAZ 21043 modification was supplemented with a system for cleaning and heating the rear door window. Information on the diagrams is intended for self-repair of a car. The wiring diagrams are divided for ease of viewing through a computer or phone into several blocks, there are also files in the form of a single picture with a description of each element - for printing on a printer.

VAZ-2104 scheme (old version)

1. block headlights;
2. - side direction indicators;
3. - accumulator battery;
4. - starter relay;
5. - electropneumatic carburetor valve;
6. - carburetor microswitch;
7. - generator 37.3701;
8. - motoreducers of headlight cleaners;
9. - electric motor of the fan of the engine cooling system *;
10. - sensor for turning on the fan motor *;
11. - sound signals;
12. - ignition distributor;
13. - spark plug;
14. - starter;
15. - gauge for the coolant temperature gauge;
16. - engine compartment lamp;
17. - sensor of the control lamp of oil pressure;
18. - ignition coil;
19. - brake fluid level sensor;
20. - gear motor of the windshield wiper;
21. - control unit for the carburetor electro-pneumatic valve;
22. - electric motor for headlight washer pump;
23. - the electric motor of the windshield washer pump;
24. - brake light switch;
25. - relay-breaker of the windshield wiper;
26. - instrument lighting regulator;
27. - relay-interrupter of alarm and direction indicators;
28. - reversing light switch;
29. - a socket for a portable lamp *;
30. - cigarette lighter;
31. - glove box lighting lamp;
32. - mounting block;
33. - light switches on the front door racks;
34. - light switches on the rear door pillars;
35. - shades;
36. - parking brake warning lamp switch;
37. - switch of the control lamp of the air damper of the carburetor;
38. - switch for the cleaner and washer glass of the tailgate;
39. - alarm switch;
40. - three-lever switch;
41. - ignition switch;
42. - ignition relay;
43. - outdoor lighting switch;
44. - rear fog light switch;
45. - Fog light circuit fuse;
46. - control lamp for oil pressure;
47. - a combination of devices;
48. - control lamp for fuel reserve;
49. - fuel level indicator;
50. - ceiling lighting for the rear of the passenger compartment;
51. - battery charge indicator lamp;
52. - coolant temperature gauge;
53. - control lamp of the carburetor air damper;
54. - parking brake warning lamp **;
55. - block of control lamps;
56. - control lamp for rear fog light;
57. - control lamp for heating the glass of the tailgate;
58. - control lamp for brake fluid level;
59. - voltmeter;
60. - speedometer 2104;
61. - control lamp for outdoor lighting;
62. - indicator lamp for direction indicators;
63. - high beam control lamp;
64. - heater fan switch;
65. - switch for heating the glass of the tailgate with a backlight lamp;
66. - heater fan electric motor;
67. - additional resistor of the heater electric motor;
68. - the electric motor for the washer pump for the glass of the tailgate;
69. - rear lights;
70. - gearmotor for tailgate glass cleaner;
71. - pads for connection to the rear window heating element;
72. - license plate lights;
73. - sensor for level indicator and fuel reserve.

a- headlight block, headlight and tailgate glass cleaners, windshield wiper relay-breaker, carburetor electro-pneumatic valve control unit; b- mounting block and three-lever switch; v- rear lights (pin numbering in order from top to bottom); G- relay-interrupter of alarm and direction indicators.

Wiring diagram VAZ 2104

Scheme VAZ-2104, for cars of early years of production. It is distinguished from the standard circuit by the G-222 generator, a 10-pin alarm switch, a 5-pin turn signal and alarm relay, a top dead center sensor for the 1st cylinder, a diagnostic block, a rear window heating indicator lamp directly in the switch , the absence of a warning lamp for the carburetor air damper, an on-off switch for external lighting and a three-position steering column light switch.

1 - block headlights;

3 - storage battery;
4 - relay of the control lamp of the battery charge;

6 - sensor of the top dead center of the 1st cylinder;
7 - carburetor microswitch;
8 - generator G-222;
9 - gearmotors of headlight cleaners *;
10 - electric motor of the fan of the engine cooling system *;
11 - sensor for turning on the fan motor *;
12 - sound signals;
13 - ignition distributor;
14 - spark plugs;
15 - starter;
16 - gauge for the coolant temperature gauge;
17 - engine compartment lamp;
18 - sensor of the control lamp of oil pressure;
19 - ignition coil;
20 - brake fluid level sensor;
21 - windshield wiper motor;
22 - control unit for the electric pneumatic valve of the carburetor;
23 - headlight washer pump electric motor *;
24 - windshield washer pump electric motor;
25 - diagnostics block;
26 - brake light switch;
27 - windshield wiper relay;
28 - relay-interrupter for alarm and direction indicators;
29 - reversing light switch;
30 - socket for a portable lamp;
31 - cigarette lighter;
32 - lamp for lighting the glove box;
33 - mounting block (a jumper is installed instead of the short circuit relay);
34 - light switches on the front door racks;
35 - light switches on the rear door racks;
36 - plafonds VAZ 2104;
37 - parking brake warning lamp switch;
38 - rear window cleaner and washer switch *;


41 - ignition switch;
42 - instrument lighting switch;
43 - outdoor lighting switch;
44 - rear fog light switch;
45 - control lamp for oil pressure;
46 - instrument cluster;
47 - control lamp for fuel reserve;
48 - fuel level indicator;
49 - plafond for lighting the rear of the passenger compartment;
50 - control lamp of the battery charge;
51 - coolant temperature gauge;
52 - relay-interrupter of the parking brake control lamp;
53 - block of control lamps;
54 - control lamp for brake fluid level;
55 - control lamp for rear fog light;
56 - control lamp of the parking brake;
57 - voltmeter;
58 - speedometer;
59 - control lamp for outdoor lighting;
60 - indicator lamp for direction indicators;
61 - control lamp for high beam headlights;
62 - heater fan switch;
63 - rear window heating switch with a control lamp *;
64 - heater fan electric motor;
65 - additional resistor of the heater electric motor;
66 - rear window washer pump electric motor;
67 - rear lights;
68 - rear window wiper motor *;
69 - pads for connection to the rear window heating element;
70 - license plate lights;
71 - sensor for the level indicator and fuel reserve.

Wiring diagram - full view:

Diagram of VAZ-21043 and VAZ-21047 carburetor

1 - block headlights;
2 - side direction indicators;
3 - storage battery;
4 - starter activation relay;
5 - electric pneumatic valve of the carburetor;
6 - carburetor microswitch;
7 - generator 37.3701;
8 - gearmotors of headlight cleaners *;
9 - electric motor of the fan of the engine cooling system;
10 - sensor for switching on the fan motor;
11 - sound signals;
12 - ignition distributor;
13 - spark plugs;
14 - starter VAZ 21047;
15 - gauge for the coolant temperature gauge;
16 - engine compartment lamp;
17 - sensor of the indicator of insufficient oil pressure;
18 - ignition coil;
19 - sensor of the indicator of insufficient level of brake fluid;
20 - windshield wiper motor;
21 - control unit for the electric pneumatic valve of the carburetor;
22 - headlight washer pump electric motor *;
23 - windshield washer pump electric motor;
24 - reversing light switch;
25 - brake signal switch;
26 - alarm relay and direction indicators;
27 - windscreen wiper relay;
28 - mounting block;
29 - light switches on the front door racks;
30 - light switches on the rear door racks;
31 - diode for checking the serviceability of the indicator lamp for insufficient level of brake fluid;
32 - plafonds;
33 - parking brake indicator switch;
34 - indicator lamp for insufficient level of brake fluid;
35 - signaling unit;
36 - plug socket for a portable lamp **;
37 - lamp for lighting the glove box;
38 - switch for the cleaner and washer of the glass of the rear door;
39 - alarm switch;
40 - three-lever switch;
41 - ignition switch;
42 - ignition relay;
43 - econometer;
44 - instrument cluster; 45 - switch of the indicator of covering the air damper of the carburetor;
46 - battery charge indicator lamp;
47 - indicator lamp for covering the air damper of the carburetor;
48 - indicator lamp for turning on direction indicators;
49 - speedometer;
50 - fuel reserve indicator lamp;
51 - fuel level indicator;
52 - instrument lighting regulator;
53 - hours;
54 - cigarette lighter;
55 - fog light circuit fuse;
56 - heater fan electric motor;
57 - additional resistor of the heater electric motor;
58 - electric motor for the pump washer glass for the tailgate;
59 - switch for rear fog light with a switch on;
60 - heater fan switch;
61 - switch for heating the glass of the tailgate with a switch on;
62-switch for outdoor lighting;
63 - voltmeter;
64-lamp signaling device for turning on outdoor lighting;
65-headlight high beam indicator lamp;
66 - low oil pressure warning lamp;
67 - parking brake activation lamp;
68 - tachometer;
69 - coolant temperature gauge;
70 - rear lights;
71 - pads for connection to the rear door glass heating element;
72 - sensor for the level indicator and fuel reserve;
73 - plafond for lighting the rear of the passenger compartment;
74 - license plate lights;
75 - gear motor for the tailgate glass cleaner.

Wiring diagram - full view:

Scheme for the injector VAZ-2104

1 - electric motor of the fan of the engine cooling system;
2 - mounting block;
3 - idle speed regulator;
4 - electronic control unit;
5 - octane potentiometer;
6 - spark plugs;
7 - ignition module;
8 - crankshaft position sensor;
9 - electric fuel pump with a fuel level sensor;
10 - tachometer;
11 - control lamp "CHECK ENGINE";
12 - vehicle ignition relay;
13 - speed sensor;
14 - diagnostics block;
15 - nozzle;
16 - adsorber purge valve;
17, 18, 19 - fuses for the injection system;
20 - ignition relay of the injection system;
21 - relay for turning on the electric fuel pump;
22 - inlet pipe electric heater relay;
23 - electric heater of the inlet pipe;
24 - fuse for the inlet pipe heater;
25 - oxygen concentration sensor;
26 - coolant temperature sensor;
27 - throttle position sensor;
28 - air temperature sensor;
29 - absolute pressure sensor;

• A - to the “plus” terminal of the storage battery;
• B - to terminal “15” of the ignition switch;
• P4 - relay for turning on the fan motor.

Wire connections in the instrument cluster

Brake system VAZ 2104

1. Brake fluid level sensor built into the expansion tank cover;
2. Electronic mounting block in the engine compartment with an "A" terminal to the generator;
3. Ignition relay with negative ground terminal;
4. Steering column ignition switch;
5. A control lamp on the instrument panel, signaling a low level of brake fluid;
6. Control lamp about the activated parking brake.

Engine fan circuits

Diagram of switching on headlights and foglights

1 - block headlights; 2 - mounting block 2104; 3 - switch for headlights in a three-lever switch; 4 - outdoor lighting switch; 5 - rear fog light switch; 6 - rear lights; 7 - fuse for the rear fog light circuit; 8 - a control lamp of a fog light, located in the block of control lamps; 9 - a control lamp of a high beam of headlights, located in the speedometer; 10 - ignition switch; P5 - relay for turning on the high beam headlights; P6 - relay for switching on the dipped headlights; A - view of the headlamp plug connector: 1 - dipped beam plug; 2 - high beam plug; 3 - plug mass; 4 - side light plug; B - to terminal 30 of the generator; B - terminals of the printed circuit board of the rear lamp (numbering of the terminals from the edge of the board): 1 - to ground; 2 - to the brake light lamp; 3 - to the side light lamp; 4 - to the fog light lamp; 5 - to the reversing lamp; 6 - to the direction indicator lamp.

Electrical equipment of the rear of the car

Fuse and relay box VAZ-2104

The newer "sevens" have a block with 17 fuses and 6 relays. Fuses VAZ 2107 on the "new" block protect the following electrical circuits and devices:

1. Reversing lamps, heater fan, warning lamp and relay for heated rear window, rear wiper motor and rear washer pump.
2. Front wiper motor.
3. Backup socket.
4. Backup socket.
5. Power supply for heated rear window.
6. Clock, cigarette lighter, power socket "carry".
7. Signal and radiator fan.
8. Direction indicator lamps in emergency gang mode.
9. "Fog" and a relay that regulates the voltage of the on-board network.
10. Instrument panel lamps.
11. Brake light lamps.
12. Right high beam headlamp.
13. Left high beam headlamp, high beam warning lamp.
14. Parking lights (rear right, front left), room and engine compartment lighting.
15. Parking lights (rear left, front right), glove compartment and cigarette lighter lamps.
16. Low beam (right lamp).
17. Low beam (left lamp).

The block relays perform the following functions:

1. Rear window heating relay.
2. Relay for cleaner and headlight washer.
3. Signal relay.
4. Cooling fan relay.
5. High beam relay.
6. Low beam relay.

Car modifications

VAZ-2104... The basic version of the station wagon, with a carburetor engine from a VAZ-2105, a volume of 1.3 liters and a capacity of 64 horsepower. Equipped with a 4-speed gearbox.

VAZ-21041... A prototype of a station wagon, a carburetor engine from a VAZ-2101 with a volume of 1.2 liters and a power of 62 hp was installed on it. Just like the base model, it was equipped with a 4-speed manual transmission.

VAZ-21042... Export version, the steering wheel was located on the right. The car also received a carburetor engine from the VAZ-2103, with a volume of 1.5 liters and a power of 72 hp.

VAZ-21043... The car was equipped with electrics and interior from the VAZ-2107, some copies had a VAZ-2106 interior. The carburetor engine was borrowed from the VAZ-2103. The gearbox was both 4 and 5-speed.

VAZ-21044... Export model, equipped with a VAZ-2107 engine with a volume of 1.7 liters with single injection, as well as a 5-speed gearbox.

VAZ-21045... Export modification with a 1.8 liter engine, did not get into mass production.

VAZ-21045D... It was produced in small batch since 1999, it was equipped with a VAZ-341 diesel engine with a volume of 1.52 liters and a capacity of 50 horsepower. The gearbox is 5-speed.

VAZ-21047... A prototype with an engine from a penny. An improved version of the Quartet, equipped with a VAZ-2107 interior and a VAZ-2103 carburetor engine with a volume of 1.5 liters and a power of 72 hp. The gearbox is 5-speed. On export modifications, the radiator grill was installed from the VAZ-2107.

VAZ-21048... Diesel station wagon with a 1.77 liter VAZ-343 engine. The gearbox is 5-speed.

VAZ-21041i... A car equipped with a VAZ-21067 injection engine. volume of 1.6 liters. The gearbox is 5-speed. Electrical equipment and interior from the VAZ-2107 car, and the front seats from the Izhevsk hatchback IZH-2126.

VAZ-21041 VF... Salon, electrics and front seats as in the previous modification, also borrowed from the VAZ-2107 radiator grill. It was equipped with a 1.5 liter injection engine from the VAZ-2103 and a 5-speed manual gearbox.

The engine cooling system is liquid, closed type, with forced circulation of liquid. The capacity of the system is 9, 85 liters, including the heating system of the interior of the body. The cooling system consists of the following elements: a coolant pump 36, a radiator, an expansion tank 8, pipes and hoses, a fan 19, block cooling jackets and a cylinder head. When the engine is running, the liquid heated in the cooling jackets enters through the outlet 6 through hoses 5 and 7 into the radiator or thermostat, depending on the position of the thermostat valves. Next, the coolant is sucked in by the pump 36 and supplied again to the cooling jacket. The cooling system uses a special liquid TOSOL A-40 - an aqueous solution of Tosol-A antifreeze (concentrated ethylene glycol with anticorrosive and antifoam additives with a density of 1, 12-1, 14 g / cm2). TOSOL A-40 blue with a density of 1.078-1.085 g / cm2, has a freezing point of minus 40 C. The coolant level is checked on a cold engine (at a temperature of plus 15-20 C) according to the liquid level in the expansion tank 8, which should be 3-4 mm above the "MIN" mark. The density of the liquid is checked with a hydrometer during vehicle maintenance. With an increase in the density of the liquid and a lower level, distilled water is topped up. At normal density, the liquid of the brand that is in the cooling system is topped up. With a reduced density of the coolant and the need to operate the car in the cold season, the fluid is replaced with a new one. To monitor the coolant temperature, there is a sensor installed in the cylinder head and an indicator on the instrument panel. Under normal temperature conditions of engine operation, the pointer arrow is at the beginning of the red field of the scale within 80-100 C. The transition of the arrow to the red zone indicates an increased thermal regime of the engine, which may be caused by malfunctions in the cooling system (weakening of the pump drive belt, insufficient amount of cooling liquid or thermostat malfunction), as well as difficult road conditions. The fluid from the system is drained through the drain holes closed with plugs: one in the left corner of the lower radiator tank 33, the other in the cylinder block on the left in the direction of the vehicle. The car's interior heater is connected to the cooling system. The heated fluid from the cylinder head enters through hose 4 through the heater radiator tap, and is sucked out by pump 36 through hose 3 and pipe 1. The coolant pump is a centrifugal type, driven from the crankshaft pulley by a V-belt to drive the generator. The pump is attached to the cylinder block on the right side through a gasket with bolts with a tightening torque of 22-27 Im (2.2-2.7 kgcm). The body 30 and cover 25 of the pump are cast from an aluminum alloy. A roller 27 is installed in the cover in a bearing 24, which is locked by a screw 28. Bearing 24 is double-row. non-separable, without an inner cage. The bearing is filled with grease during assembly and is not greased in the future. On the roller 27, on the one hand, the impeller 31 is pressed, and on the other, the hub 26 of the pump drive pulley. Impeller end. in contact with the O-ring, hardened by high frequency currents to a depth of 3 mm. The O-ring is pressed against the impeller by a spring through a rubber cuff 29. The oil seal is non-separable, consists of an outer brass cage 23, a rubber cuff and a spring. The oil seal is pressed into the pump cover 25. The pump housing has an inlet 32 ​​and a window 22 towards the cylinder block for pumping coolant. With normal tension of the pump drive V-belt, the belt deflection under a force of 100 N (10 kgf) should be in the range of 10-15 mm. Fan The fan 19 is a four-blade impeller made of plastic, which is bolted to the hub 26 of the pump drive pulley. The fan blades have a radially variable installation angle and, to reduce noise, a variable step along the hub. For better efficiency, the fan is housed in a shroud 18. bolted to the radiator brackets. Radiator and expansion tank. Radiator with upper 14 and lower 33 tanks, with two rows of vertical brass tubes 16 and tinned cooling plates 17, is fastened with four bolts to the front of the body and rests on rubber supports 21. The filler neck 15 of the radiator is closed with a stopper AND and is connected by a hose 10 with a translucent plastic expansion tank 8. The radiator plug has an inlet valve 13 and an outlet valve 12, through which the radiator is connected with a hose to the expansion tank. The inlet valve is not pressed against the gasket (clearance 0.5-1.1 mm) and allows the inlet and outlet of coolant into the expansion tank when the engine is heated and cooled. When a liquid boils or a sharp increase in temperature due to a small throughput, the inlet valve does not have time to release liquid into the expansion tank and closes, disconnecting the cooling system from the expansion tank. When the pressure increases when the liquid is heated to 50 kPa, the outlet valve 12 opens and a part of the coolant is discharged into the expansion tank. The expansion tank is closed with a plug, which has a rubber valve that operates at a pressure close to atmospheric. Since 1988, radiators with aluminum cores made of two rows of horizontal circular aluminum tubes and aluminum cooling plates began to be installed on the engines of VAZ2105, -2104 cars. Two-way radiator with plastic tanks and nozzles for connecting hoses. One of the tanks has a partition. The radiator is collapsible, the core is attached to the tanks through rubber gaskets. To increase the efficiency of liquid cooling, aluminum cooling plates are stamped with a notch, and plastic turbulators in the form of corkscrews are inserted into some of the tubes. All this ensures the turbulent movement of air and liquid in the tubes. It must be remembered that it is not recommended with aluminum radiators to use water in the cooling system as a coolant in order to prevent corrosion of the aluminum pipes. Thermostat and Cooling System Operation The coolant thermostat accelerates engine warm-up and maintains the required engine temperature. Under optimal thermal conditions, the coolant temperature should be 85-95 "C. Thermostat 38 consists of a body 43 and a cover 46, which are sealed together with the seat of the main valve 41. The thermostat has an inlet 40 for inlet of cooled liquid from the radiator, a bypass hose 44 5 for bypassing fluid from the cylinder head to the thermostat and a branch pipe 45 for supplying coolant to the pump 36. The main valve is installed in the thermoelement glass, in which the rubber insert 39 is rolled. The rubber insert contains a polished steel piston 47, fixed on a stationary holder. a thermosensitive solid filler is placed by walls and a rubber insert. The main valve 41 is pressed against the seat by a spring. The valve is equipped with two posts, on which a bypass valve 42 is installed. through the radiator or bypassing it. On a cold engine with a coolant temperature below 80 C, the main valve is closed, the bypass valve is open. In this case, the liquid circulates through the hose 5 through the bypass valve 42 to the pump 36, bypassing the radiator (in a small circle). This ensures that the engine warms up quickly. If the temperature of the liquid rises above 94 ° C, the thermostat's temperature-sensitive filler expands, compresses the rubber insert 39 and squeezes out the piston 47, moving the main valve 41 until it is fully open. The bypass valve 42 closes completely. In this case, the liquid circulates in a large circle: from the cooling jacket through the hose 7 to the radiator and then through the hose 34 through the main valve enters the pump, which is again directed to the cooling jacket. Within the temperature range of 80-94 C, the thermostat valves are in intermediate positions, and the coolant circulates in small and large circles. The opening value of the main valve ensures gradual mixing of the liquid cooled in the radiator, thereby achieving the best thermal mode of the engine operation. The temperature of the beginning of the opening of the main thermostat valve should be within 77-86 C, the valve stroke should be at least 6 mm. Checking the start of opening of the main valve is performed in a water tank. The initial water temperature should be 73-75UC. The water temperature is gradually increased by 1 ° C per minute. The temperature at which the valve starts opening is taken as the temperature at which the stroke of the main valve is 0.1 mm. The simplest test of the thermostat operation can be carried out by touch directly on the car. With a working thermostat, after starting a cold engine, the lower radiator tank begins to heat up when the arrow of the liquid temperature indicator on the instrument panel is approximately 3-4 mm from the red zone of the scale, which corresponds to a coolant temperature of 80-95 C.

11 1. Pipes for draining fluid from the heater radiator to the coolant pump. 2. Hose for removing the coolant from the inlet pipe. 3. Hose for removing coolant from the heater radiator. 4. Hose for supplying fluid to the heater radiator. 5. Thermostat bypass hose. 6. Cooling jacket outlet. 7. Radiator supply hose. 8. Expansion tank. 9. Tank cap. 10. Hose from the radiator to the expansion tank. 11. Radiator cap. 12. The outlet (steam) valve of the plug. 13. Inlet valve plug. 14. Upper radiator reservoir. 15. Radiator filler neck. 16. Radiator tube. 17. Radiator cooling plates. 18. Fan casing. 19. Fan. 20. Pulley for the drive of the coolant pump. 21. Rubber mount. 22. Window on the side of the cylinder block for supplying coolant. 23. Oil seal holder. 24. Coolant pump roller bearing. 25. Pump cover. 26. Fan wheel hub. 27. Pump roller. 28. Locking screw. 29. Oil seal collar. 30. Pump casing. 31. Pump impeller. 32. The inlet of the pump. 33. Lower radiator tank. 34. Outlet radiator hose. 35. Radiator belt. 36. Coolant pump. 37. Hose for supplying coolant to the pump. 38. Thermostat. 39. Rubber insert. 40. Inlet pipe (from the radiator). 41. Main valve. 42. Bypass valve. 43. Thermostat housing. 44. Branch pipe of the bypass hose. 45. Branch pipe of a hose for supplying coolant to the pump. 46. ​​Thermostat cover. 47. Piston of the working element. 48. I. Scheme of the thermostat. 49. II. The liquid temperature is less than 80 C. 50. III. The liquid temperature is 80-94 C. 51. IV. The liquid temperature is more than 94 C.