One of my back brakes is sticking i believe. It's making a squeeling noise when driving and when i apply brake, it's a terrible unhealtyh sounds (dont know how to describe it really)... they are probably really old pads (not too sure cause i only bought the car 6 months ago and forgot to ask about brakes).. Would it be sticking cause of worn pads? or would this be a caliper problem?

 

your caliper may be seized, if there is alot of brake dust in your wheel then you know thats the problem.

 

I'm thinking that you're grinding the rotor...

 

If the caliper is seized, does the whole thing need to be replaced? or can it just be loosened or fixed somehow?

 

It's more than likely a pad that's worn all the way down to the backing.

Pull the wheel off and see if there's any "meat" left on the pad.

If there is, take it for a quick spin after it's cooled off for a while. Brake one or two good hard times, then park it. Pull the wheels off and either touch them (if you're brave) or spit on them and see if the one you suspect of being stuck is much hotter than the others.