Help! Just recently my 2001 f-150 developed a squealing noise around the front right tire. The noise occurs when the truck is in motion and gets worse when the brakes are applied especially right before the truck stops. It does not matter what speed the truck is going. The problem is that it does not occur all of the time. I may be driving for an hour and it doesn't happen, then all of the sudden it will start. I may stop and begin driving again and it will go away. I took it into the shop and wouldn't you know, it did not do it for them. The brakes are only a year old and the shop said they couldn't find anything. I am thinking that it could possibly be something in the 4 wheel drive mechanisms but I'm not sure. Can anyone help?????