Attention! A hot engine can cause burns.
Sequence of work
"120,000 km every 4 years"
1. Carefully remove the expansion tank cap.
2. Release excess pressure from the cooling system.
3. Set the heating control on the dashboard to «Heiss» (hot). This opens the cooling circuit of the heating system.
4. Remove the crankcase protection.
Pic. 4.45. Radiator drain plug: 1 - fitting for a hose nozzle; 2 - plug
5. Place a receiving container under the radiator and engine, unscrew the drain plug on the bottom of the radiator (pic. 4.45) and drain the coolant. Attach a short hose to the fitting on the side (inner diameter - 12 mm), to direct the liquid into the container.
6. Put on the hose (inner diameter - 14 mm) drain plug on the right side of the engine block and open it.
7. Remove the cap from the expansion tank.
8. Drain the coolant and close the receiving container.
9. Screw on the plugs on the engine block and on the radiator.
10. Slowly fill in coolant through the filler neck on the expansion tank to the mark.
11. Start the engine and let it run at high speed for about 2 minutes. At the same time, constantly add coolant to the expansion tank.
12. Close the cover of the expansion tank.
13. Leave the engine running until the fan turns on.
14. Stop the engine.
15. If necessary, add coolant up to the marking.
16. Warm up the engine. In this case, the air from the cooling system will exit through the cap of the expansion tank. With the engine cold, check the coolant level again. Top up with a little water if necessary.
17. Replace the crankcase protection.
Antifreeze bay
If you want to check the antifreeze content of the coolant, you need a hydrometer, which measures the specific gravity (density) liquids.
Attention! Daimler-Benz only allows the use of homemade antifreezes. In case of malfunctions caused by the use of antifreeze from other manufacturers, the warranty is void. Do not add more than 50% antifreeze to increase the frost resistance of the coolant, this will adversely affect its cooling properties. If you do not have a special hydrometer for antifreeze, subtract +2...+3°C from the average value measured with a conventional hydrometer.
Sequence of work
1. Remove the crankcase protection.
2. Place a collecting container under the radiator and engine.
Pic. 4.46. Antifreeze concentration indicator (hydrometer)
3. Remove the coolant from the expansion tank or unscrew the drain plug on the radiator and drain approximately 1-2 liters of coolant (pic. 4.46).
4. Add the required amount of antifreeze to the expansion tank. Top up the remaining drained fluid if necessary.