do i need a new ps pump?

[92SVXLS-LDC]

when my car is cold, there is a faint squealing noise until i either rev the engine a little bit, or turn the wheel... then its a horrendous squealing noise... i checked out whats happening under the hood, and the power steering pully is definately stopping when the wheel turns... the dealer tried telling me its most likely the belt is too loose? but wouldnt it make more sense if it was too tight??? and when it heats up its "okay"... and it sounds like you cant just replace the pulley, right? power steering pump? advice is appreciated....