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  • Flushing coolant is important because coolant breaks down over time, becoming acidic and therefore corrosive.
  • To flush coolant, it’s important to use safety equipment such as goggles and gloves since it is made of toxic chemicals.
  • Some shops have a dedicated machine for flushing coolant, but the job can also be done at home with a bottle of radiator flush/cleaner.

Nearly every vehicle manufacturer recommends a coolant flush as part of their maintenance schedule—it’s an essential part of any car care routine. Why? Because coolant breaks down over time and becomes acidic. And when that happens, it can eat away at the various metal components found throughout the engine and cooling system.

Many late-model vehicles have organic additive technology (OAT) coolant that lasts longer than traditional, green inorganic additive technology (IAT) coolant. Still, even these more advanced formulas require a periodic flush or exchange.

The good news is, with the right tools and a little know-how, you can easily do a coolant flush at home.

Be careful when handling coolant because it contains toxic substances.

How to Do a Coolant Flush

Most professional repair shops use a dedicated machine to perform coolant flushes—but you can use a bottle of radiator flush/cleaner to do a similar job at home.

Are you ready? Good! Let’s get started!

Tools Needed for a Coolant Flush:

The tools needed to do a coolant flush will vary, depending on what type of car you have. In general, however, you’ll need:

  • 50/50 pre-mixed coolant (consult your owner’s manual to determine the correct type of coolant for your vehicle)
  • Air compressor (recommended)
  • Cooling system vacuum fill tool (recommended)
  • Distilled water
  • Fluid catch pan
  • Fluid container
  • Jack and jack stands
  • Pliers
  • Screwdrivers
  • Radiator flush
  • Repair manual or access to a repair database
  • Safety glasses
  • Wheel chocks
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opening radiator cap
Make sure the engine is cool before opening the radiator cap.

Coolant Flush Instructions:

Before we begin, keep in mind: all vehicles are different. The information below is generic and for entertainment and educational purposes only. Be sure to follow the repair information for your specific application.

Repair manuals, such as those from Chilton, are useful, but a subscription to a repair database is even better. ALLDATA and Mitchell 1 both have single-vehicle subscriptions for DIYers that provide detailed factory repair information.

You can learn more about accessing quality repair information in this article.

pouring coolant into the radiator
Top off the coolant as needed and reinstall the radiator cap.

Now, let’s get down to flushing your coolant. Here’s how it’s typically done:

  1. Put on your safety glasses.

  2. Make sure the engine is off and cool.

    Warning: Hot coolant can cause severe personal injury. Make sure the engine is cool before proceeding.

  3. Safely raise and support the vehicle using a jack and jack stands. Set the parking brake and chock the rear wheels.

  4. Place a fluid catch pan under the vehicle.

  5. Remove the radiator cap.

  6. Drain the old coolant. You can do this by either disconnecting the lower radiator hose (recommended) or by opening the radiator drain petcock. Disconnecting the lower radiator hose is the safest route since petcocks can become brittle and break.

    To disconnect the lower radiator hose:
    -Make sure the fluid catch pan is under the lower radiator hose.
    -Use a pair of pliers or a screwdriver (depending on the clamp design) to loosen the hose clamp.
    -Wiggle the lower radiator hose while pulling it toward you to disconnect it from the radiator.
    -Allow the coolant to drain into the fluid catch pan.

  7. Reinstall the lower radiator hose and tighten down its clamp.

  8. Follow the instructions on the flush/cleaner you’re using to add the correct mixture of flush and distilled water to the radiator.

  9. Follow the instructions on the product to run the flush through the cooling system.

  10. Wait until the engine has cooled down completely.

  11. Place the fluid catch pan under the vehicle.

  12. Disconnect the lower radiator hose (as outlined earlier) to drain the flush mixture from the cooling system.

  13. Reinstall the lower radiator hose and tighten the clamp.

  14. Safely remove the jack stands and lower the vehicle.

  15. Follow the instructions that come with the cooling system vacuum fill tool to connect the tool to your air compressor. The tool bleeds the cooling system of air while simultaneously refilling the coolant.

  16. Follow the instructions that come with the tool to refill the cooling system with a 50/50 mix of fresh coolant.

  17. If you do not have access to an air compressor and vacuum fill tool, consult a repair manual or repair database for the cooling system bleeding instructions for your vehicle.

    Warning: If you do not properly bleed the air from the cooling system, overheating and engine damage may result.

  18. Top off the coolant as needed and reinstall the radiator cap.

  19. Make sure the vehicle doesn’t overheat by starting the engine and monitoring the temperature gauge. Do this until the engine reaches operating temperature, and the cooling fan kicks in.

  20. Pour the old coolant and flush from the catch pan into a large fluid container.

  21. Make sure to clean up any fluid spills with a rag. Coolant is deadly if consumed, and animals are attracted to it.

  22. Check online to find out where you can recycle your old coolant (pouring it down the drain is illegal). Usually, you can get rid of it at a landfill that accepts hazardous waste.

  23. After driving the vehicle for a day or two, re-check the coolant level and top off as needed.
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Here’s a helpful video on how to change your coolant:

Where to Get New Coolant for Your Vehicle

Whatever you put into your vehicle can significantly affect its performance 一 the same way humans have to watch what they eat. If you’re a dedicated DIYer who likes to perform fluid flushes and replacements in their own garage, it’s important to get products that passed stringent testing procedures.

Here at, we have a great selection of coolants and other car fluids. Not only do we source them from only the best aftermarket brands today, but our industry professionals also handpicked them to ensure their quality.

Find a compatible coolant for your vehicle by entering its year, make, and model into our vehicle selector. You can also use the search filters to narrow down the catalog according to your preferences.

Order now, and check out securely in a matter of minutes. You can also place your order by calling us on our toll-free hotline. Our customer service representatives are always ready to assist you 24/7.

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Enjoy the best deals when you shop from us. All our products come with a low-price guarantee to help you get the best value for your money.

Shop for coolant today, and take advantage of our unbeatable prices!

Products Mentioned in this Guide

About The Author
Written By Automotive Subject Matter Expert at

Mia Bevacqua has over 14 years of experience in the auto industry and holds a bachelor’s degree in Advanced Automotive Systems. Certifications include ASE Master Automobile Technician, Master Medium/Heavy Truck Technician, L1, L2, L3, and L4 Advanced Level Specialist. Mia loves fixer-upper oddballs, like her 1987 Cavalier Z-24 and 1998 Astro Van AWD.

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.

File Under : DIY , Cooling System Tagged With :
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