ATX, Auto, Ford, Uncategorized
Leave a Comment

How To: Flush Your Radiator & Change Coolant

While the official start to summer is still about a week away, those of us in Texas are definitely already feeling the heat. Having a vehicle A/C that works properly is absolutely a must with this 100+ degree weather. That’s why it’s vital to ensure that your radiator has recently been flushed and that your coolant has been changed. Not sure how to do the flushing or change? Your friends at Leif Johnson Ford are here to give you simple and step-by-step instructions!


  1. Open the radiator fill cap. This can usually be found on the top of the radiator. If your vehicle has a plastic tank or reservoir for coolant, go ahead and open that too.
  2. Now it’s time to check your vehicle’s owner manual. First, look for the location of the radiator petcock. (Petcock = Small valve) Position the petcock underneath this area to capture the antifreeze.
  3. Open the drain and let all coolant drain into this container until it ceases to flow. Proceed to close the petcock/drain.
  4. Now it’s time to pour your radiator flush product (such as Ironite ThoroFlush 468-9110-16) into the radiator. Take your garden hose and fill the radiator until it’s about one inch below radiator neck. From there, follow the directions on your radiator flush product.
  5. Close the caps to your radiator and reservoir.
  6. Turn your heater on high and run your engine for approximately ten minutes after it reaches operating temperature. Turn car off until your engine and radiator are cool to the touch.
  7. Close the petcock or drain after you have drained the radiator. Refill the system with water and put caps back on. Once the engine has reached operating temperatures, run the heater on high again for ten minutes. Let cool once again.
  8. Remove caps and repeat step 3.
  9. Place used coolant in a closed container and drop off at your closest recycling center. You will probably have a lot of diluted and used coolant by the time you are finished with this process.
  10. Now it’s time to refill your radiator with pre-diluted coolant! Make sure that it’s the type approved by your vehicle’s manufacturer. (If you are using a full strength coolant, use diluted water. It’s a good rule of thumb to use 50/50 water and coolant in most climates.)
  11. Run your engine until the cooling system ceases to bubble and the coolant level begins to rise. Put the radiator cap back on the system. If your car has a coolant bleed screw, use this in lieu of the radiator cap method.
  12. Check the radiator coolant level once again. Add more coolant in the radiator and the plastic tank if the coolant isn’t reaching the “full level” indicator.
  13. You’re almost done! Go ahead and close and tighten the radiator cap and reservoir cap. Check the coolant a day or two later to ensure it is still looking nice and full.
  14. That’s all, folks! In the winter, consider using an antifreeze tester to check the lowest possible temperatures that your coolant can reach without freezing. Other than that, you should be good to go. This is a relatively simple process that is safe for beginners to tackle!

If you need absolutely any help at all, feel free to call your friends at Leif Johnson Ford with questions or to schedule an appointment! 


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s