Kendine iyi bak! = Take care!

so if kendin translates as yourself, add the -e suffix(to/go) and kendine translates as yourself go, roughly. 

iyi means good, or maybe care in this case

does bak mean take? because i cant find bak to translate as take or take/take care to translate as bak in the online dictionary. 

 It´s the imperative form of ´bakmak´ ´to look´ or ´to look after´

So literally it means ´look after yourself well´

I think bak comes from bakmak. You could also say look after yourself, but it has the same meaning as take care! It`s just the turkish way of saying it

thanks for that, very helpfull i understand that phrase now