Mercedes C-Class

W203 since 2000 of release

Repair and operation of the car

+ Mercedes-Benz cars of class C (W-203)
+ Operation manual
+ Routine maintenance
+ Engine
- Cooling system and heating
   - Cooling system
      Antifreeze - a security measure from freezing
      Replacement of cooling liquid - general comments
      Removal and replacement of hoses of the cooling system
      Removal and installation of the thermostat
      Check of the thermostat
      Check of the cooling system under pressure
      Removal and installation of the pump of cooling liquid
      Removal and installation of the fan
      Removal and installation of a radiator
   + Systems of ventilation, heating and air conditioning
+ Power supply system and release
+ Engine electric equipment
+ Manual transmission
+ Automatic transmission
+ Coupling and power shafts
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment

Replacement of cooling liquid - general comments

Address also the Section Check of Functioning of the Cooling System and Frost Resistance of Cooling Liquid. Liquid replacement.

Cooling liquid has to be replaced at repair of the cooling system at which liquid merges. In case at repair the head, the block, sealing laying of a head of cylinders, a radiator, the heat exchanger or the engine are replaced, then cooling liquid has to be replaced. In the course of circulation anticorrosive additives are besieged on new details from light metal and by that form a durable anticorrosive layer. In the used cooling liquid of anticorrosive additive, as a rule, it is already not enough to form a sufficient protective layer on new details.

 Attention! The merged cooling liquid should not be applied again. Cooling liquid is poisonous and should not merge with household waste.



1. Install the regulator of a heater of salon on the maximum value of temperature.
2. Lift the car and install it horizontally on supports. Lifting operation and installations of the car on supports is connected with danger! Therefore before carrying out operation study Poddomkrachivaniye's Section and towage of Introduction to the management.

 At the hot engine before opening of a broad tank cover it with a thick rag to exclude a burn owing to influence of hot cooling liquid and steam. It is necessary to uncover only at a temperature of cooling liquid below +90 °C.

3. Open a cover (1) of a broad tank (2). At the warm engine put a thick rag on a cover. Turn a cover a little to the left and dump pressure in the cooling system. Then completely turn off a cover.

4. Put pure capacity under a radiator and the block of cylinders.

5. Open a drain stopper (3) on a radiator (4) and let's cooling liquid merge in the substituted capacity.

To provide exact hit of liquid in capacity, put on a hose a branch pipe (5).

Cooling liquid can be merged also from the block of cylinders. In this case put on a hose the drain union in the right part of the block of cylinders. Open the union for a hexagon and merge liquid in the substituted capacity. The moment of an inhaling is specified in Specifications.

6. Completely merge liquid.
7. Wrap a drain stopper on a radiator and remove a drain hose.
8. Lower the car on wheels.

Filling of system with liquid


1. Prepare new cooling liquid.
2. Fill in liquid through a broad tank.

Fill system with liquid slowly, watching that airbags were not formed.

3. Check the level of cooling liquid, address the Section Check of Levels of Liquids, control of leaks.

Removal of air from the cooling system


1. Start the engine at uncovered a broad tank and let's the engine work on single turns.
2. Install the heater regulator in salon on the maximum value of temperature.
3. You watch liquid level in a broad tank, supplementing it to the mark MAX.
4. Warm up the engine up to the temperature of cooling liquid of 60 - 70 °C or before heating of the top hose of a radiator. After that close a cover of a broad tank.
5. Let's the engine work with turns 1500 – 2000 in a minute so that the fan of a radiator turned on and was again switched off.
6. After that stop the engine.
7. Visually check the cooling system, in particular, of accession of hoses, and also a drain stopper and the pump of cooling liquid for tightness.
8. Let's the engine be cooled and check the level of cooling liquid, if necessary add liquid.