I have a 1999 chevy camaro and I need to add coolant. do I add coolant to resevoir only or to radiator only or to both?

Just had a go-round with same problem in an 87 Cavalier. Had to take off radiator cap, add coolant, squeeze bottom radiator hose. After no more bubbles, add coolant, squeeze top radiator hose. Squeeze bottom again. Add coolant as needed. The air was because it was run low when the radiator cap gasket failed and coolant boiled out. Never got the overheat notice on digital dash or idiot light. Make sure you have a new radiator cap.

youcan put it straight into resevoir but it would be better to find the leak and repair it ,,. cost you less in repairs in long run

there are lines that go to your transmission to the side of the radiator maybe one of the are bad

Yes, you can put it directly in the radiator. You may have a resevoir you can add more coolant in, also. Either one is okay. I much more prefer to add it directly to the radiator. Just please make sure it is completely COOL before you open it. If not, then open it very slowy. When you take the pressure off of it, the water/coolant will instantly boil and explode. I still have the scars of removing a cap that I thought was cool enough.

YOU NEED TO ADD MORE COOLANT IN THE OVER FLOW JUG. YOUR OVER FLOW JUG IS WHERE YOU POUR COOLANT TO FILL UP RADIATOR. KEEP POURING COOLANT DOWN THE OVER FLOW JUG UNTIL COOLANT STOP DROPPING AND STAY AT THE FULL COLD MARK.KEEP EYE ON OVER FLOW JUG DONT LET RUN DRY BECAUSE AIR WILL BE PULLED IN THE COOLANT SYSTEM CAUSE A LOT OF ENGINE OVER HEATING PROBLEMS.

There is a coolant expansion tank (WHITE OR OFF WHITE)..not the windshield washer !!
The coolant tank should have a strongly made cap where the washer will just have a flip up cap.
DO NOT PUT COOLANT IN WASHER ...COOLANT WILL RUIN WINDSHIELD.
Some of the tanks are kinda hidden.Best to look in owners manual...it will show a photo.
only certain models are added to radiator...but you should be able to see radiator cap if it is not a sealed radiator....MOST ARE SEALED RADIATORS TODAY .Some have radiator caps with a coolant resevoir just to keep it topped off...others have a coolant expansion tank and the radiator does not have a cap.

You still have air in the system. remove the radiator or resevoir cap and run the car to operating temperture, some coolant may come out at first because it's trty to purge the air. when you see that the coolant is going down, you can slowly add more coolant , as the car is still running

Check that your electric radiator fan is working. When the car is hot and idling it should come on.

Replace your therostat. I had a Chevy Citation that the thermostat would start to open and then close instead of opening all the way.

fill the raditor to the top only when cold, top off the coolant bottle level to full cold, reinspect the coolant bottle after the engine get to proper operation temputure and add coolant to the bottle only. NEVER take off the radiator cap when hot!

Always fill you radiator & resevoir with a 50/50 mix of coolant / water. Your vehicle should have dexcool which is a red/orange colored coolant. You can buy a universal equivalent which is premixed and is yellow (not green). It is safe to add universal coolant but not green antifreeze. Premixed (it will say on jug) would be your safe bet. Fill the radiator, add to overflow tank to full cold line, run vehicle until fully warmed up. Let cool back down & then recheck.
Don't forget to check for leaks....it is not normal to have your coolant get that low. You likely are leaking coolant.

If this helps please rate me!
You can do it.
Brett