Engine coolant

How much coolant should be added to my radiator. The reservior is empty. And when I took the radiator cap off (using a flash light the level was barely visable) the manual states the radiator holds 12.8 quarts. So obviously the levels are low. My question is should I fill the radiator or through the reservior to what level?

First, do you have “premixed” coolant (50% water) or straight anitfreeze (no water added)? If you have premixed, you don’t need to add water. If you have straight coolant, you need to make a mix of half antifreeze and half water.

Then remove the radiator cap and fill full to the very tip-top. Reinstall the cap, and make sure it locks on.

Then look at the reservoir. There should be “min” and “max” marks. Fill the reservoir to the “max” mark and replace the cap.

You’re done!

The radiator should be FULL…There should also be a line on the reservoir showing what the cold and hot levels should be. Keep an eye this…if you continuously loose coolant then there’s a reason for it…and needs to be looked at.

Edit: “if you have straight antifreeze, you need to make a mix of half antifreeze and half water.”

Use distilled water, not tap water for best results.

As others have said, the purpose of the resevoir is to keep the radiator full. As the coolant heats up or cools down, it will push excess to the tank and then draw it back in again. So you fill the radiator up to the top, then the tank to the recommended level, then check the tank level after some heating cooling cycles.

If you have lost that much coolant, you need to have it pressure tested to find and repair leak. Neglecting to do that could lead to catastrophic engine damage.

You should fill bothe the radiator and the reservoir…and then do a compression test on the system to find out where the leak is. Or else you’ll end up with an overheated and possibly destroyed engine. You ARE losing fluid, and the problem will not correct itself.

You can buy coolant already 50/50 mixed, that is what you should be using. If you have straight antifreeze, you need to get some distilled water and make a 50/50 mix. About a quart should be enough.

Fill the radiator with the 50/50 mix up to the top and put the cap on. Make sure it is on tight. Then add 50/50 mix to the overflow tank. Over the next few days as you use the car some air will move from the radiator and block into the overflow tank and the level in the tank will go down. A good time to refill the tank is in the morning when the car is cold from sitting overnight.

After a few days the level in the tank should be about one inche above the min. mark and stay there. That means you finally have all the air out of the system. If the level keeps dropping you have a problem. Either a leak or perhaps an internal problem in the motor, ie. bad head gasket.