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Coolant
The coolant consists of a mixture of antifreeze and water with the addition of a corrosion protection additive. Mercedes is poured into the cooling system of its engines concentrate chemical composition of which is designed specifically for the engines of the company. The proportions of water and antifreeze depend on the total amount of the coolant in each type of engine. The proportion of anti-freeze should be 50% - it protects the fluid from freezing at -37 ?� C. When the content of more than 50% antifreeze deteriorates the heat transfer of the coolant. If the proportion is less than 40% antifreeze, deteriorating its action primarily corrosion protection, while negative coolant temperature begins to thicken. Important: if you want to top up the coolant, it is not necessary to add only distilled water, it is also necessary antifreeze and corrosion protection. Coolant level sensor Coolant level sensor for gasoline engines has the same structure as the sensor for diesel engines. All practical advice, work on the verification of the sensor and its operation are similar to those described for the diesel engine in Section 4 "diesel engines." Substitution coolant
"120 000 km every 4 years" 4-cylinder engine 1. Carefully unscrew the expansion tank cap, drain the excess pressure of the cooling system.
A WARNING Be careful with the hot engine can cause burns. |
2. Set the heater on the instrument panel to the maximum heating. 3. Remove the crankcase from below.
| Fig. 5.26. Radiator drain plug 1 - cork
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4. Place a receptacle under the radiator and the engine at the bottom of the radiator, unscrew the drain plug 1 (Fig. 5.26), and drain the coolant. On the side of fitting can be put on short hose (internal diameter 12 mm) to direct the liquid into the container.
| Fig. 5.27. Putting a hose fitting cylinder 1 - a hose
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5. Put the hose 1 (Fig. 5.27), an inner diameter of 14 mm on the right side of the drain fitting on the engine block and open it. 6. To better coolant merged, remove the cap from the expansion tank. Drain the coolant and cover receptacle. 7. When complete draining radiator coolant flush with clean water. 8. To fill the coolant screw plug on the engine block and the radiator drain plug. 9. Install the crankcase.
| Fig. 5.28. Radiator filler neck
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10. Slowly pour the coolant through the filler neck (Fig. 5.28), the fluid level should reach the ledge at the bottom of the surge tank (visible when the lid is open), which corresponds to a distance of 5.5 cm to the upper edge of the filler neck. 11. Start up the engine and let it run at high speed about 2 minutes. The heater is set at maximum heating. At the same time constantly top up the expansion tank with coolant. 12. Screw the expansion tank cap. 13. Run the engine before turning on the fan, and then stop the engine. 14. Check the coolant level, top up if necessary. 15. Warm up the engine. This cooling system will go through the expansion tank cap. Recheck the coolant level. If necessary, add a little water. Features replacing coolant 6-cylinder engine 1. Turn 1/2 turn a two-stage expansion tank cap and remove the pressure in the system. Turn the cover and remove it.
NOTE At 6-cylinder engine cover has a two-stage pressure. As a result, after the engine system pressure may rise to 2 bar, and the liquid will not leak. |
2. Before filling the system, remove the temperature sensor in the thermostat housing. 3. Fill cooling system until the liquid will flow out of the holes of the thermostat. 4. Turn the temperature gauge and add fluid to the norm. 5. Screw the lid so that the projection on the expansion tank locks. Features replacing coolant 8-cylinder engine 6. The engine has a two-stage expansion tank cap. 7. In the engine block has two drain valves.
Coolant Testing Before the onset of cold weather Regularly check the antifreeze concentration in the coolant, especially if you are in the period of operation were added to the system water. To verify the required densitometer - density measuring. The resulting density can translate into the value of the freezing point of the coolant.
1. Start up the engine and warm it up until the upper pipe for supplying coolant to the radiator does not become warm. 2. Carefully open the expansion tank cap.
A WARNING There is a danger of burns. |
| Fig. 5.29. Coolant Testing using densimeter
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3. Vberite densimeter coolant and determine the density of the float (Fig. 5.29).
NOTE The concentration of antifreeze for our latitude is to prevent freezing of the cooling water to a temperature of -37 ?� C for areas with cold climates - to -45 ?� C. |
A WARNING Daimler-Benz allows you to use only self-made antifreeze. If faults have arisen because of the use of anti-freeze from other manufacturers, the warranty expires. |
4. Add the antifreeze in the cooling system in the amount specified in the Table. 5.5 to provide the necessary temperature in the freezing operation of the vehicle in the region.
Table 5.5. Displacement antifreeze concentrate to obtain the desired freezing temperature coolant
Example of use of the table. If the density of the coolant on the engine working volume 2.0 L corresponds to the freezing temperature -10 ?� C, to obtain the freezing point of -37 ?� C, 3.1 L must be drained of coolant and pour in the same amount of the antifreeze concentrate. For freezing point -45 ?� C is necessary to replace the 3.7 liter. 5. Close the lid of the expansion tank, make a test drive, again check the antifreeze concentration.
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