Cooling system — flushing

1. Over time, the cooling system may gradually lose efficiency as the radiator core becomes clogged with rust, water scale and other deposits. To minimize this, Nissan recommends using good quality antifreeze and soft water. The system must be flushed every time the coolant is replaced. Continue as follows.

2. Drain the coolant, install the lower hose, or close the drain plug, and fill the system with fresh water. Install the radiator cap, start the engine and warm it up to normal operating temperature, then stop and (waiting until it cools completely) drain the system again. Repeat as necessary until clean water flows from the system. Finally, fill the system with the specified coolant mixture.

3. If the specified mixture was used and replaced at the specified intervals, the above procedure will be sufficient to keep the system clean for a considerable time. If these recommendations are neglected, it is necessary to perform a more complete rinse as follows.

4. Before flushing the system, first drain the coolant as described in previous Chapter.

5. Disconnect the upper hose from the thermostat housing, and disconnect the lower hose (if not already disconnected) from the radiator outlet pipe.

6. Insert a garden hose into the top hose and run water through the radiator until it comes out clean from the bottom outlet.

7. To flush the engine, remove the thermostat as described in Chapter 11, insert a garden hose into the thermostat housing. Run water through the engine until it comes out clean from the bottom hose. Finally, install the thermostat.

8. In case of serious contamination, you can backflush the radiator. To do this, remove the radiator as described in Chapter 9, turn it over and insert a garden hose into the bottom outlet. Flush until water comes out clean from the top hose outlet.

9. The use of chemical filters is permitted only when absolutely necessary. By regularly replacing antifreeze, excessive contamination of the system is avoided.