flexfactor

Lately I've noticed that my 2005 F-150 brakes just fine no squeaks until I come to a complete stop. When my truck hits the complete stop and settles, I hear a high pitched squeak coming from the rear it seems. I went to Les Shwab and had my brakes checked. I have 45,000 miles on my truck and the brakes are low. However, I've never experienced "low brakes" to squeak at the end of a stop? Any ideas of what this could be? I'm hoping to just change my front and rear pads, resurface the rotars, and do a brake fluid flush..... but will this most likely cure the problem? Any help?