- Drain the cooling system completely as described earlier.
- Close the petcock and fill the system with a cooling system flush (clean water may also be used, but is not as efficient).
- Idle the engine until the upper radiator hose gets hot.
- Allow the engine to cool completely and drain the system again.
- Repeat this process until the drained water is clear and free of scale.
- Flush the recovery tank with water and leave empty.
Never open, service or drain the radiator or cooling system when hot; serious burns can occur from the steam and hot coolant. Also, when draining engine coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze and could drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantities. Always drain coolant into a sealable container. Coolant should be reused unless it is contaminated or is several years old.
- Fill and bleed the cooling system as described earlier.