Radiator Flush Cost: Parts, Labor & Average Price

A radiator flush, also called a coolant flush or cooling system flush, replaces the old coolant in the engine, radiator, and hoses with fresh coolant. Over time coolant loses its protective additives, and it can pick up rust and deposits. Fresh coolant helps the system resist corrosion and keeps the engine at a steady temperature.

Shops use two methods. A drain-and-fill removes the coolant that drains out and refills the system. A machine flush pushes new coolant through the system and pulls out more of the old fluid. Both are sold as a "radiator flush," so the same name can cover jobs that cost different amounts.

ThePricer puts a professional radiator flush at $100 – $250, and says many drivers pay $130 – $210. A lower-cost independent shop may charge $100 – $150, while a dealer coolant flush runs $200 – $250. Large-capacity or specialty systems cost $200 – $300. A DIY coolant change or flush costs $25 – $75 for coolant and supplies.

Jerry lists a basic drain-and-fill with no machine flush at $80 – $150, and its average for a cooling system flush at most shops is $173 – $184.

The base flush price does not always include everything. Some shops charge more for a machine flush, for a specialty coolant, or for work done at the same visit.

A machine power flush usually adds $30 – $80 compared with a simple drain-and-fill. Certain coolant formulations or a larger system capacity add $20 – $60. If the thermostat is replaced while the system is open, the cost is $150 – $350, and a new radiator cap costs $10 – $30. Hazardous waste or shop supply fees can also appear on the bill.

Dealers typically charge the most and follow the manufacturer's coolant specification. Independent shops and quick-lube chains often charge less. A low advertised price may cover only a drain-and-fill, so ask what the price includes. Coolant type matters too. Many vehicles require a specific coolant, and mixing types can cause problems, so confirm the shop uses the correct coolant for your car.

Follow the interval in your owner's manual, which gives the manufacturer's schedule for your engine. A technician may also recommend a flush if the coolant looks rusty or cloudy, or if a test strip shows the additives are used up. A flush is a maintenance service. It is not the fix for overheating, which can come from a thermostat, a water pump, a leak, a failing radiator, or a fan problem. If your car is overheating, have the cause diagnosed rather than assuming a flush will solve it.

Hot coolant is under pressure and can cause serious burns. Never open a radiator cap or coolant reservoir on a hot engine. Used coolant is toxic to people and pets, and it must be disposed of properly, so shops handle it as a regulated waste. For these reasons, many owners leave this service to a shop. If you do your own, work only on a cold engine and follow the manual for your vehicle.

• Drain-and-fill or machine flush.
• Coolant type and system capacity.
• Vehicle make, since some luxury and specialty vehicles cost more.
• Condition of the coolant and the system.
• Add-ons such as a new thermostat, cap, or hoses.
• Shop type, location, and fees.

The three ranges above all describe a professional flush, but they are built differently. Jerry reports an average across most shops, so its range is narrow. The Kelley Blue Book figure, which ThePricer cites, is also an average. ThePricer's own range spans quick-lube chains, independent shops, and dealers, so it is wider. A source that counts a drain-and-fill alongside a machine flush will show a lower number than one that counts only machine flushes. Vehicle mix, region, and whether fees are included may explain the rest.

• Is this a drain-and-fill or a machine flush?
• Which coolant is being used, and is it right for my car?
• Does the price include disposal and shop fees?
• Will you check the hoses, cap, and thermostat?
• Is the service covered by any maintenance plan I have?