Flushing engine coolant involves draining the old coolant into a container, adding water to the cooling system, and repeating the draining process. The final step involves filling the system with the new coolant.
Ensure that the engine has cooled down before commencing the flushing process. Parking the car on a ramp gives a good ground clearance for flushing but is not mandatory. Position a container beneath the radiator drain plug, and open the plug to drain the old antifreeze. After completely draining the old coolant, replace the drain plug, and fill the system with plain water to dilute the remaining antifreeze. Run the engine to achieve operating temperature, and allow the water to circulate in the system. Switch off the engine before repeating the draining process.
Refill the system with distilled water to remove any mineral deposits that may damage the cooling system over time, and repeat the draining process. When the drain water is clean, allow all the water to exit the system, and restore the drain plug. Mix the new coolant with water according to the manufacturer's instructions. Fill the mixture in the cooling system until the coolant reaches a maximum in the radiator reservoir. Restore the radiator cap, and run the engine with the heater turned on High until the temperature gauge returns to its normal range. Turn the vehicle off, and dispose of the old coolant in adherence to environmental regulations.