How to refill radiator after fixing coolant leak?

I got home tonight and smelled coolant. Looked under the car, coolant everywhere. I see the issue: a big hose (maybe 2" in diameter) has a tear in it and is spraying out coolant. I’m going to replace it, but once I do, how should I add coolant back into the radiator? Do I just pour it into the overflow? Thanks.

2002 toyota camry 4 cylinder

Edit: thank you everyone for your help! I bled the radiator and it was quite simple. Car runs great now.

The best advice i can offer is to see it done in a video. You have to pour it into the radiator, and then start the car when it gets full to purge air from the system while adding more coolant.

Make, model, and year please.

2002 toyota camry 4 cylinder

If your radiator has a cap on it, remove the cap and fill it first. Use a funnel and either discard the funnel afterwards or mark it “Anti-freeze only” add put it up somewhere out of the reach of children. Anti-freeze is very toxic if ingested.

You can make a funnel out of an old plastic milk bottle or oil bottle.

After you fill the radiator, the fill the overflow reservoir up to the cold mark only. Do not fill it up.

If your radiator does not have a cap, then fill the overflow up to the fill line.

You may nee to bleed the system, let us know what make and model vehicle and we can advise.

I should also mention that it was an upper hose that sprang the leak.

Once the repair has been made, add a 50/50 mix of anti-freeze/water to the radiator until it’s full.

Start the engine, and let it idle until the the thermostat opens and you see a drop in the coolant level. While the engine is still idling, add coolant to the radiator until it’s full and shut the engine off and install the radiator cap.

After a half hour, check the level in the coolant reservoir and add coolant as required.


The inquires above are to determine your car’s cooling system configuration. It is critical to make sure the engine and radiator are full of coolant , not just the plastic bottle where you normally add coolant to top it off. It’s possible after hose leaks for the engine and radiator to have little to no coolant in them, while the bottle appears full, and that condition is what you have to avoid.

If I did that job on my Corolla (for reference) – 10 years older than your Camry so the cooling system configuration may not be the same as yours – I’d remove the radiator cap (when the engine is cold) and fill the radiator to about 2 inches below the brim with a 50/50 mixture. Then I’d turn the heater temp control to “max”, start the engine and let it warm up while idling with the radiator cap off, and watch – takes about 5 minutes or so of idling – for the thermostat to open and hot water to start pouring into the upper part of the radiator. It’s clear when that happens on my engine configuration. Feeling the upper radiator hose get hot all of a sudden confirms it. After a couple minutes of that, all the air would be bled out, so then I’d stop the engine, let it cool off again, then top the radiator right to the brim, install the radiator cap then fill the bottle to the cold fill mark. Check for leaks, and watch for any signs of over or under-heating while driving the first few times. Done.

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In addition to all the good advice you’ve gotten above, consider replacing all of the coolant hoses. Oftentimes the weakest one lets go, and then when you replace that, the next weakest one lets go and you dump all your coolant again. Easier to just replace everything while you’re already under there with an empty system. Don’t forget about the heater hoses in the back.

This answer fixed my issue, i have a 2001 dodge dokota, and the upper hose had broken. After replacing the hose i was overheating. I my truck the radiator fill is actually on the upper radiator hose and just filling the reservoir did not get enough coolant into the system. After using this suggestion but filling though the cap on the upper hose problem fixed.

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Glad that idea helped you out @Christopher_Manuel . Back on the road with a cool-running Dakota. What’s not to like :slight_smile: