at what mileage should you flush coolant
When circulation is complete, the coolant or antifreeze mixture is then drained and replaced with the standard mix of coolant and water. There is no set rule for how often a vehicle needs a radiator flush. Car manufacturers recommend that it be done at least every other year or every 40,000 to 60,000 miles. Occasionally flushing the radiator before that period is not a problem as it helps to clean and prevent build up of dirt and sediment.