Started having a rear brake squeel when coming to stops at around 34,000 miles. It is now 43,000 miles and it has been in the Ford dealership 3 times. Shoes & Pads have all been replaced with some special TSB replacement type. Last time even put some type of special magnets to the rear brakes. The dealer said it would probably come back and it did. It is sooooo annoying. Any advice how to fix it?