8. Over time, the cooling system may gradually lose efficiency if the radiator matrix becomes clogged with scale and rust. In this case, the system must be flushed as follows.
9. Drain system, install drain plug and motor bottom shield, fill with clean water.
10. Install the expansion tank filler cap, start the engine, and warm it up to normal operating temperature. Then turn off the engine and drain the fluid. Repeat the procedure as needed until only clean water flows out, then fill the system as specified in Specifications coolant.
11. If the specified in Specifications coolant and changed at the indicated intervals, the above procedure will be sufficient to keep the system clean for a very long time. Otherwise, you will need to follow these steps.
12. First, drain the coolant, this time disconnecting the lower hose from the radiator, then disconnect the upper hose from the thermostat housing (photo). Insert a water hose into the top hose, and run water through the radiator until it comes out clean from the bottom hole.
13. To flush the engine cooling jacket, insert a water hose into the thermostat housing and run water through the engine until it comes out clean from the bottom hose. If after some time the water does not become clear, the system must be flushed with a special cleaner, such as Holts Radflush or Holts Speedflush.
14. In case of severe contamination, reverse flushing can be performed. To do this, remove the radiator (Section 3), turn it over and insert the water hose into the bottom outlet. Run water through the radiator until it comes out clean from the top hole. A similar procedure can be used to flush the heater matrix.