Hi I have a 1990 f150 xlt lariat 4.9 L. My engine squeals upon startup and gets worse if I turn on the ac when the engine is warming up. After that its fine. The power steering pump pulley has some give to it though. About 1/16". When the engine is running it doesnt seem to wobble at all. Have replaced the belt and the tensioner w pulley. Cleaned all the pulleys as well. Trying to fix this terrible sound and need help! It would be much appreciated my friend.
Use a straight edge and check alignment of belt if the pump wobbles with the belt off see why a bent pulley can make the belt go bad and then check for oil on pulleys if any clean it all off and stop where it is coming from.