Mercedes W124

since 1985-1995 of release

Repair and car operation

W124 Mercedes
+ Governing bodies and control devices
+ 2. Maintenance (diesel engines)
+ 4. Repair of 6-cylinder petrol SOHC engines
+ 5. Repair of 6-cylinder petrol DOHC engines
+ 6. Repair of the diesel engine established in the car
+ 7. Major maintenance of engines
   8.2. General information
   8.3. Hoses of system of cooling
   8.4. Radiator
   8.5. Thermostat
   + 8.6. Radiator fan
   8.7. Electric sensors
   + 8.8. Water pump
   8.9. Heating and ventilation system
   + 8.10. Elements of system of heating
   8.11. Air central air
+ 10. System of injection of BOSCH CIS-E fuel (KE-JETRONIC)
+ 11. System of injection of BOSCH HFM fuel
+ 12. Fuel system of diesel engines
+ 13. Fuel system of diesel engines
+ 15. System of ignition of 4-cylinder petrol engines
+ 16. System of ignition of four-cylinder petrol engines
+ 19. Mechanical transmission
+ 20. Automatic transmission

8.2. General information

The system of cooling of tight type turns on the water pump with a drive from an auxiliary driving belt, the radiator fan with the termovyazkostny or electromagnetic coupling, a radiator with a cross-section or descending stream, a broad tank and perelivny a tank, the thermostat and a heater radiator, and also hoses and switches. At start of the cold engine cooling liquid circulates round the block of cylinders and a head of the block of cylinders. Warm cooling liquid passes through the heater fan to the water pump. As cooling liquid when heating extends, its level in a broad tank raises. Intake of cooling liquid through a radiator is closed that provides the closed thermostat. When cooling liquid will reach the predetermined temperature, the thermostat opens and hot cooling liquid passes through a hose to a radiator. As cooling liquid passes through a radiator, there is its cooling by a stream of counter air. The Termovyazkostny coupling of the fan of a radiator turns on depending on air temperature behind a radiator. At achievement of the predetermined temperature the valve in the coupling opens and the termovyazkostny coupling puts in action a krylchatka of the fan of a radiator. At temperature reduction the termovyazkostny coupling reduces transfer of a torque and rotation of the fan of a radiator is slowed down. The electromagnetic coupling of the fan of a radiator turns on термодатчи a lump, established in cooling system. At turning on of the coupling its coupling and the fan of a radiator joins starts to rotate from an auxiliary driving belt. At reduction of temperature of cooling liquid below предопреде lenny value the electromagnetic coupling is switched off, therefore the krylchatka of the fan of a radiator rotates freely. At overflow of a broad tank cooling liquid goes in perelivny a tank which is established on an internal arch of the right wheel.

On a number of models cooling liquid also passes through the heat exchanger of engine oil placed under a casing of the oil filter.

For ventilation of salon of the car air moves through a lattice in a back part of a motor compartment. If necessary the stream of air can be increased by means of the heater fan. From salon air is removed via channels in a back part of the car. For heating of the air arriving in salon of the car, air is passed through a heater radiator.


When opening a cover of a broad tank on the hot engine it is necessary to be careful, as leaving pairs can lead to strong burns. For this purpose close a cover of a broad tank a thick layer of a fabric and slowly unscrew a cover before emergence of a hissing sound. After the hissing termination slowly unscrew, and uncover a broad tank.

Do not allow hit of cooling liquid on clothes and a paint and varnish covering of a body. Otherwise wash out a surface a plentiful quantity of water.

After switching off of the hot engine the radiator fan can turn on.