Cooling System Maintenance: Flushing

Back flushing is very effective procedure for removing rust and scale from cooling system. Radiator, engine and heater core should be flushed separately for best results.
To flush radiator, connect flushing gun to water outlet of radiator and disconnect water inlet hose. Use 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, 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. Ensure heater control valve is set to maximum heat position before flushing heater.