Cooling System Servicing: Maintenance: Flushing

WARNING: This page is about a different car, the 1988 Pontiac 6000, 1988 Oldsmobile Cutlass Cruiser, 1988 Oldsmobile Cutlass Ciera, 1988 Chevrolet Celebrity, and 1988 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.

Back flushing is a very effective means of removing rust and scale from a cooling system. For best results the 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. To prevent flooding engine, use a leadaway hose connected to radiator inlet. Use air in short bursts only; this will prevent damage to radiator. Continue flushing until water runs clear.
To flush engine, first remove thermostat and replace 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 set to maximum heat position before flushing heater.