Cooling System Service: Drain and Refill

The Drain and Fill method of servicing your car's cooling system is quick, easy, and straightforward.

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These instructions should be used as only advice. Always follow your car's manufacturer's instructions when servicing it on your own.

Drain, Fill, Repeat... Easy as 1-2-3
1. Start with a Cool Engine. Make sure your vehicle has not been driven for several hours before starting this maintenance job. If you need more clearance to access the under side of the radiator, jack the front of your car up and support it on jack stands or use a set of ramps.
2. Remove the Radiator Cap and set it aside. (Fig. A)
3. Locate the Radiator Drain, it will probably be on the side of the radiator opposite from the radiator cap, located towards the very bottom of the radiator. (If your car does not have a radiator drain, skip to step 6). (Fig. B, 1=Draincock, 2=Drain)
4. Attach a Hose to the radiator drain, if needed, and route it to a large container capable of holding at least 5 gallons. (Fig. C)
5. Loosen the Draincock to open the drain. Let the old coolant drain out of the radiator (this may take 10-15 minutes depending on the size of the radiator). When all the old antifreeze has drained, tighten the draincock and proceed to step 8.
6. Locate the Lower Radiator Hose. This will be a large hose coming out of the bottom of the radiator.
7. Remove the Lower Radiator Hose, being careful to not get antifreeze on yourself. Remove the hose by disengaging the hose clamp with a tool appropriate to the type of clamp used (pliers or screw driver). Route the hose so that it will empty into a large container. When all the antifreeze has drained, reinstall the hose.
8. Fill the Radiator with distilled water. Optionally, you can use tap water from a garden hose, but tap water is often hard (mineral rich) and can leave mineral deposits inside the radiator or heater core which can, in turn, block coolant passages.
Reinstall the radiator cap.
9. Turn Your Heat on High (Fig. D)
10. Run the Engine Until it Warms Up, as indicated by the temperature gauge or the radiator fan turning on. Let the engine run for about 10 minutes AFTER it gets to normal operating temperature. (Fig. E)
11. Turn Off the Engine and let it cool down. Then drain the radiator again.
12. Fill the Radiator with a 50/50 blend of antifreeze and distilled water. Pour the blend in slowly and use a funnel to help avoid spills. Once the radiator is full, leave the radiator cap off and leave the funnel in place.
13. Burp the Radiator by running the engine again for a few minutes with the radiator cap off. Any air bubbles will eventually find their way to the radiator fill neck and escape with the cap off. During the air's escape, antifreeze can bubble and burp out of the radiator, so keep some rags around and leave the funnel in the radiator to help keep things tidy.
14. Top Off the radiator with your blended 50/50 antifreeze/water.

Summary
To summarize:

1. Remove the radiator cap and drain the radiator.
   
2. Fill the radiator with distilled water.
3. Run the engine until it gets to normal operating temperature, and then for 10 minutes longer.
4. Shut off the engine and drain the radiator.
5. Fill the radiator with a 50/50 blend of antifreeze and distilled water.
6. "Burp" the system by running the engine with the radiator cap off.
7. Top off the radiator with a 50/50 blend of antifreeze and distilled water.
   

End Notes
While performing this maintenance, check all the cooling system components for wear and tear. Replace any hoses that show signs of imminent failure, such as cracks, bulges, swelling, or punctures.

After completing this maintenance, your vehicle's cooling system should be ready to perform at its peak for at least a couple of more years!

*ALWAYS make sure you dispose of used antifreeze in accordance to your local laws!

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Similar Pages
Here are some links to pages with information relevant to this article.

Coolant Flush Main Article
Flush and Fill Instructions
Flushing Kit Instructions
Cooling System Overview
What Type of Coolant Does My Car Use?

Automotive Home Outdoors Tool Talk Miscellany