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.
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
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.
Now, let’s get down to flushing your coolant. Here’s how it’s typically done:
- Put on your safety glasses.
- Make sure the engine is off and cool.
Warning: Hot coolant can cause severe personal injury. Make sure the engine is cool before proceeding. - Safely raise and support the vehicle using a jack and jack stands. Set the parking brake and chock the rear wheels.
- Place a fluid catch pan under the vehicle.
- Remove the radiator cap.
- 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. - Reinstall the lower radiator hose and tighten down its clamp.
- Follow the instructions on the flush/cleaner you’re using to add the correct mixture of flush and distilled water to the radiator.
- Follow the instructions on the product to run the flush through the cooling system.
- Wait until the engine has cooled down completely.
- Place the fluid catch pan under the vehicle.
- Disconnect the lower radiator hose (as outlined earlier) to drain the flush mixture from the cooling system.
- Reinstall the lower radiator hose and tighten the clamp.
- Safely remove the jack stands and lower the vehicle.
- 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.
- Follow the instructions that come with the tool to refill the cooling system with a 50/50 mix of fresh coolant.
- 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. - Top off the coolant as needed and reinstall the radiator cap.
- 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.
- Pour the old coolant and flush from the catch pan into a large fluid container.
- Make sure to clean up any fluid spills with a rag. Coolant is deadly if consumed, and animals are attracted to it.
- 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.
- After driving the vehicle for a day or two, re-check the coolant level and top off as needed.
Here’s a helpful video on how to change your coolant:
How Often Should You Flush Coolant?
You should flush your vehicle’s coolant based on the interval in your owner’s manual. Most manufacturers recommend flushing the coolant every 2 years or 30,000 miles, but it’s always best to check the manual.
Also inspect the coolant hoses and radiator cap in case the rubber’s broken down over time. It’s best to replace these components every 5 years. The top and bottom radiator hoses especially need attention. As for the radiator cap, if the spring inside is rusty or the rubber gasket’s dried out or crumbling, it’s time for a change. A faulty cap might allow the radiator to operate beyond safe operating temperatures.
How To Tell When To Flush Coolant
Regularly check the coolant in the radiator reservoir. If the coolant is murky, thick, or cloudy, that’s another sign it’s time for a coolant flush. Here are more symptoms of poor coolant quality:
- An illuminated check engine light
- Engine temperature gauge hitting the red zone
- An illuminated low coolant/antifreeze warning light
- Cool air blowing out from the vents even on a hot setting
These symptoms can serve as early warning signs. Bring your vehicle in for repairs right away when you notice them.
Benefits of Flushing Coolant
Flushing your coolant according to your vehicle’s manufacturer-recommended guidelines is sure to give you some peace of mind. At the same time, a flush removes harmful sludge and particles from the radiator and its hoses, preventing bad engine problems. New coolant lubricates the cooling system’s moving parts and extends its lifespan. Fresh coolant will also be better at protecting the engine from high temperatures and corrosion.
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 CarParts.com, 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.
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
Radiator Cap
Radiator Hose
Coolant/Antifreeze
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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.
