Depending on the model, two types of radiators are used. Models equipped with air conditioning have a light alloy cross-flow radiator with plastic cooling compartments on each side.
On models without air conditioning, a gravity-flow light alloy radiator is installed with plastic cooling compartments at the top and bottom. Additionally, on models equipped with an automatic transmission, the transmission fluid heat exchanger is built into either the right or bottom cooling compartment.
The thermostat is a two-way valve that has a main channel that opens at a certain temperature, allowing coolant to flow through the radiator, and a bypass channel that opens when the main channel is closed. This allows coolant to flow through the engine and the interior heater.
The vane type water pump is located at the front of the engine and is driven by a belt from the crankshaft pulley.
The electromagnetic radiator fan is mounted on the water pump spindle and works in tandem with temperature sensors installed in the cylinder head. When the coolant temperature reaches a predetermined temperature, the clutch is activated and the fan is pressed hard against the pump pulley. When the temperature drops, the clutch disengages and the fan rotates freely only under the action of air pressure when the car is moving forward.
The plastic expansion tank is located on the right side of the engine compartment and collects the liquid that is forced out of the system during thermal expansion. As the liquid cools, it returns to the radiator.
Precautionary measures
Warning.
- Do not attempt to remove the expansion tank cap to fill the cooling system while the engine is hot, as there is a high risk of scalding. If the expansion tank cap must be removed before the engine and radiator have cooled completely (even if it is not recommended). It is necessary to reduce the pressure in the cooling system first. To avoid burning, cover the cap with a thick cloth and slowly unscrew it until a hissing sound appears. When the hissing stops, which means the pressure has dropped, slowly unscrew the tank cap all the way and remove it; if the hissing sounds are still heard, wait until they stop. In all cases, when opening the expansion tank cap, try to keep your distance from it.
- Do not allow antifreeze to come into contact with your skin or painted surfaces of your vehicle. If this does happen, wash the stains off immediately with plenty of water. Never leave antifreeze in an open container, on the roadway, or on the garage floor. Children and pets may be attracted by the pleasant smell, but antifreeze is fatal if ingested.
- When working on vehicles equipped with an air conditioning system, certain precautions listed in paragraph 10 must be observed.
- If the engine is hot, the electric fan may start to rotate even when the engine is not running. Be careful when working in the engine compartment.
(Original source of information: www.MercedesMan.ru)