Cadillac Repair: engine squeal, cadillac seville, power steering pump

Question
my 92 cadillac seville 4.9l v8, has a high pitch squeal in the engine, runs good, everything seems to work fine, just squeals, i put a new alternator, and both pulleys(tension and idler), thinking they were the problem, and just had a new water pump installed by a mechanic (never had this problem before the new water pump), only things left are the power steering pump and ac compressor, im going crazy, lol, if you can help, it would be greatly appreciated, ty

Answer
Try spraying the belt with BELT DRESSING or SILICONE that comes in a spray can available at any auto parts store and see if the noise goes away. If it does, Replace the belt and keep the old belt in the trunk in case you break down and can't get one right away as you can use it until you can get a new one.