Engine Cooling Fan: Maintenance: Flushing

Back flushing is very effective procedure for removing rust and scale from cooling system. For best results radiator, engine, and heater core should be flushed separately.
To flush radiator, connect flushing gun to water outlet of radiator and disconnect water inlet hose. Use leadaway hose, connected to radiator inlet, to prevent flooding engine. Use air in short bursts only, as clogged radiator could be easily damaged. Continue flushing until water runs clear.
To flush engine, first remove thermostat and reinstall housing. Connect flushing gun to water outlet of engine. Disconnect heater hoses from engine. Flush using short air bursts until water runs clean. Flush heater core as described for radiator. Make sure heater valve is opened to maximum heat position before flushing heater.