what i do is fill the rad till its full, half fill the resovoir and start the engine. wen engine heats up and fan starts to kick in, the coolant level in the rad will drop , top it up and keep an eye on it for few mins. if it drops again top it off. Fill the resovoir to max level, put on rad cap and take the car for a drive. come back check coolant level, if neccessary top it up again and it shud be ok then