Coolant Flush Cost
Reviewed by GarageDex editorial
GarageDex's price data shows a shop charges $70 to $120 for a coolant drain and fill, or $100 to $250 for a full flush. The coolant itself costs $15 to $30 a gallon. For routine maintenance a drain and fill with the coolant your manufacturer specifies is usually enough.
For your exact carFind your coolant capacityLook it upCoolant service prices at a glance
| Coolant, per gallon | $15 to $30 |
|---|---|
| Drain and fill, at a shop | $70 to $120 |
| Full flush, at a shop | $100 to $250 |
Ranges aggregated from published 2026 US repair-cost and parts price guides, including RepairPal and Car Talk. Prices vary by region, brand, and vehicle - treat these as a sanity check on a quote, not a fixed price.
The mistake that costs the most
Using the wrong coolant. Colour does not identify the chemistry, and incompatible types can react and form sludge that clogs the radiator and wears out the water pump. That turns an inexpensive service into a much larger repair. Match the specification your manufacturer lists, not the colour in the reservoir.
How much you need, and when
Capacity decides how many gallons to buy. Look up your car's coolant capacity, and see how often to change coolant for the service interval. Long-life coolants last years, so many cars need this far less often than a shop may suggest.
Frequently asked
What is the difference between a coolant flush and a drain and fill?
A drain and fill empties the radiator and refills it, replacing a large share but not all of the old coolant, since some stays in the engine block and heater core. A flush pushes cleaner or fresh coolant through the whole system to replace nearly all of it, which takes longer and costs more.
Do I need a coolant flush or is a drain and fill enough?
For routine replacement on schedule, a drain and fill is usually enough. A full flush makes sense when the old coolant is contaminated, rusty, or sludgy, or when switching to a different coolant type.
How much coolant does my car need?
It depends on the engine and cooling system, commonly between one and three gallons. Look up your exact vehicle's capacity so you buy the right amount.
Can I top up with any coolant?
No. Use the coolant type your manufacturer specifies. Mixing incompatible coolant chemistries can form gel or sludge that blocks passages and damages the water pump.
Need your car's exact spec?
Find your coolant capacity