If the radiator tends to get low, then putting antifreeze in the bottle simply tops it up but won't stop it getting low again, if that's what you mean. It's not a cure for coolant loss.
You add to both the radiator cap and the overflow bottle.
You fill it to the bottom of the radiator cap, and to the full mark of the overflow bottle.
Remove the radiator cap when the engine is cool and add the coolant into the radiator or you can add to the coolant overflow bottle. DON'T remove the radiator cap when the engine is hot!!!
Antifreeze has to be put in at the overflow bottle.
The overflow bottle may overflow if: 1. The car is overheating - this means after the coolant in the radiator gets heated up and expands it flows to the reserve bottle but the radiator doesn't cool down to suck back the coolant from the overflow bottle, but just keeps on sending coolant to the bottle. 2. You may have put excess coolant in the bottle - hence heated coolant from the radiator didn't get enough space.
Bad radiator fluid.
no antifreese
Coolant is added to the overflow bottle instead of the radiator. The overflow bottle will allow fluid to fill over into the radiator.
I assume you are refering to the radiator overflow bottle. The required coolant is red 5 year antifreeze(not dexcool).
It is on the overflow bottle.
Depends what type of car, but generally it's near the radiator.
Engine is overheating.