the top plastic part of my radiator, right next to the cap, has a tiny lil crack in it. not very significant but im definitely losing radiator fluid. any cheaper way to fix this instead of replacing the radiator?

 

Nope. You can get a brand new radiator for < 100 bucks, check E or rockauto.com for example.

 

any decent jb weld or hardnening liquid that will get in the cracka dn harden. Go to local auto store and ask what they have in stock. just a suggestion.