You may be observing two separate noises for 2 different things.
The loud raspy noise you described might be a bad pump, part # 35-6780
Performa pumps are notorious for failing and get quite loud when they do. To see if this is the issue, pull the machine out from the wall a bit so you can lean it back and remove the single belt underneath. The belt just slips off. Turn the small metal pulley on the right side (pump) by hand in both directions. If this pulley grinds or is hard to turn, the pump is probably bad.
Regarding the squealing noise, all Performa and Atlantis machines made on the Herrin platform have a brake lining that squeals just like a car does when it comes to a stop. This is normal and does not affect operation one bit. Unless you have the special brake tool to remove the assembly and sand the stator area down with Emery cloth, disregard the squeal.
The other noise is not healthy, however. My 2 cents is on the pump.