MAINTENANCE EVERY 1000 OPERATING HOURS DRAINING OFF THE COOLANT 1. Switch off the engine and let it cool down. 2. Turn the radiator cap (arrow) slowly to the side, up to the first fixed stop, and let the pressure escape. Then press down the cover, while proceeding with swivelling. Then, remove the cover. 3. Stretch a tube onto the drain opening (1) of the discharge cock and insert the other tube end into the collecting con- tainer. 4. Open the discharge cock and let the coolant run off. 5. Close the discharge cock. 75_202 CLEANING THE COOLING SYSTEM The cooling system may only be filled slowly since other- wise the included air cannot escape completely. After fill- ing up, wait approx.
3 minutes and refill liquid, if required. 6. Fill up the cooling system slowly with cleaning fluid (Adhere to the specifications of the cleaning agent manufac- turer). 7. With the radiator cap opened, let the engine run for 5 min- utes with a coolant temperature of approx. 176°F (80°C). 8. After the cleaning, switch off the engine and open the drain valve to let the entire cooling system run empty. Re-lock the drain valve and slowly fill the cooling system with clean wa- ter. 9. Let the engine run for five minutes with a coolant tempera- ture of approx. 176°F (80° C). 10. Then, let the cooling system run empty again.
If the extrud- ing water is not clean, the cooling system must be re-flushed until the extruding water is clean. 11. Close the drain valve. 1 75_253 FILLING OFF COOLANT 12. Empty and clean the expansion tank. 13. Prepare the coolant as prescribed. 14. Fill off the coolant slowly into the cooling system up to the overflow shoot of the radiator. 15. To bleed the cooling system while the radiator cap is re- moved, let the engine run idle for five minutes with its lower speed (rpm) and then for another five minutes with its top speed. Fill off with coolant if the coolant level in the radiator is dropping. 16. Switch off the engine, wait approx.
three minutes and then refill coolant up to overflow shoot of the radiator. Re-lock the radiator. 17. Fill off coolant into the expansion tank, until the coolant level is between the FULL and LOW markings. 7-61