sounds?
 

when i reverse my truck i hear sqeeking sounds coming from rear when i break, what is it, only happens when i reverse and brake

Does this happen first thing in the morning or any time during the day? If it is only in the morning then it is probably moisture. Any time then it my be glaze. Hope this helps.

Yeah the same thing happens to me when in the morning when I back down my driveway and break to slow myself. It's only mositure on the pads. Like Paul said, if it happens any time of day then it might be something else like glauze. If your pads are new that is just the pads breaking in from the reverse direction, they are used to stopping forwards but backwards is another job to them. Don't worry, my girlfriend got new brakes on her Eclipse about 2 weeks ago and they still squeel in reverse breaking, but never in forwards.