I don't have any coolant in my overflow bottle, I pulled the cap off and the radiator's fluid level is right below hose from the radiator to the overflow. I have a haynes book but it is at home with the firebird and I can't remember how to fill it correctly.

Do you fill with the car on or off...what level should the coolant be in the radiator...I seem to remember something about checking that while the car is running...anyway, how do you do it?

 

Fill your overflow up to the "cold" line. When doing this make sure you take a bottle or a empty milk jug and mix half water and half coolant.
If the radiator is really low or if it goes down in a week or so then you are either burning it or you have a leak somewhere.

Oh yeah I don't think it matters that much if the car is on or off. I usually just do it with the car off unless I change the fluid and need to get the air pocket out.

 

Rememeber that the cooling suystem is pressurized so it may be better to fill it with the car turned off.

 

If you're just adding to the resevoir it doesn't matter whether it's on or off. If you're adding straight to the radiator you have to have it running so as to not cause an air pocket to form.

 

Well, I stand corrected...