Slipping drived belt?

Hey guys.

Would a slipping serpentine belt always generate squeals? I personally think that a belt won't always squeal if it is slipping. I ask because I think the belt is slipping on the way pump pully.

These won't slip unless there is no tension at all. Old trick; try spraying silicone on both surfaces of the belt and the pulleys while it's idling. If the noise stops, go ahead and use about a third of the can on it, slowly. Noise should stay away for a few weeks. Or....... just get a new belt.