A fair price for a radiator flush is a figure in line with the national average, which is between $10 and $200, as of 2015. This figure depends upon several variables, including the age, make and model of the car and the type and amount of coolant used.
The cheapest radiator flush is when the owner performs the flush himself. A do-it-yourself flush costs $13 to $34 because the only expense is the cost of supplies.
A radiator flush at an auto repair shop or oil-and-lube shop costs between $54 to $144 because of the cost of labor and supplies. The average price is $99.
A car dealership is a more expensive, with a radiator flush costing $70 to $175. The average price at a dealership is $109.