Safety Glasses
Gloves
Jack
Jack Stands
Pre-Mixed Antifreeze
Radiator Cleaner
Drain Pan
Funnel
This page and video will show the job done on a 2009 Honda Accord, but you’ll find that most vehicles are pretty similar. As always—before any job—take a look at your service manual. If you don’t feel completely comfortable doing this yourself, we can refer you to a professional technician.
Step 1: Let engine cool completely
Before doing a flush, make sure your engine is completely cool. The antifreeze can be hot enough to cause injury. Antifreeze is toxic, so put on gloves and eye protection once the engine has cooled.
Jacking up the front of your vehicle and placing it on jack stands will make it easier to work underneath the radiator, but if you have a vehicle with plenty of ground clearance, it may not be necessary.
Step 2: Find and remove your fill cap
Open your hood and find your antifreeze reservoir. To drain your old antifreeze, start by removing your fill cap. The fill cap can be on the radiator, the engine, the pressure tank or one of your hoses.
Step 3: Locate the petcock
Locate the petcock, a small shut-off valve, which will be located on the bottom of one of the radiator tanks. It’s possible that it could have a small plastic cover that can be removed with a screwdriver.
Step 4: Let the old fluid drain
Place a drain pan under the radiator and open the petcock to let the old antifreeze run out. In some cases, this will be a hose that you’ll detach to let the old fluid drain. Once the antifreeze is done draining, close the petcock.
Step 5: Recycle old antifreeze
Used antifreeze is considered hazardous waste so we are unable to recycle it in our stores. Most cities and counties have hazardous waste collection sites. We suggest you call your city or county administration or search their website for hazardous waste disposal.
Step 6: Add radiator cleaner and water
Next, add radiator cleaner and water according to manufacturer’s recommendations, and replace the cap.
Step 7: Start your vehicle
Start your vehicle, turn your heater on high until the the engine reaches normal operating temperature, then shut your engine off and let it cool down completely.
Step 8: Drain the system
Remove the fill cap and open the petcock to drain the system again. When it’s done draining, be sure to close the petcock.
Step 9: Fill the system with water
With the fill cap open, use a garden hose to fill the system with water according to manufacturer’s specifications, and replace the cap.
Step 10: Start your vehicle
Turn on the engine and let it run until it reaches normal operating temperature. Then turn off the engine and let it cool down completely.
Step 11: Drain the system again
Open the petcock and drain the system again, making sure to close the petcock when it’s done.
Step 12: Repeat the water flush process
Repeat the water flush process. Remove the fill cap and re-fill with water according to manufacturer’s specifications, and replace the cap.
You can use distilled water this time if you’re concerned about any remaining minerals from the tap water.
Step 13: Drain the water from the system
Open the petcock to drain the water from the system, and make sure you close the petcock when done.
Step 14: Refill the system
Full strength and diluted (called pre-mixed) antifreeze are available for purchase. If you're using full strength antifreeze, you'll dilute it with water. The proper ratio will typically be 50/50. If you're using a pre-mixed antifreeze, you won't need to put any water in the system.
Step 15: Let the engine run
Turn on your engine and let it run until the engine reaches normal operating temperature. Let the engine run for another ten minutes, then check under the vehicle for any leaks.
Step 16: Turn off your vehicle
Shut off the engine, and once it’s cooled down completely, double-check the antifreeze level to see if any needs to be added. If it’s at the proper level, you’re all done.
Antifreeze, or coolant, helps to keep your engine at the proper temperature and prevent corrosion. O'Reilly Auto Parts stores carry premixed and concentrated antifreeze options to best suit your vehicle.
O'Reilly Auto Parts carries radiators, water pumps, thermostats and blower motors. Keep your vehicle warm in the winter or cool in the summer with proper heating and cooling equipment for your car, truck, or SUV.
Here are some things to consider when the temperatures start to drop. Use this guide to check your fluid levels, heater, battery, and more.