When i apply brakes and back up 96 grand prix se it makes a squeaking noise only time it does this what could?

(2011-04-24 14:20:54) 1. george w Says: one of two things will do that really, brake dust which is nothing really or the pads or shoes are worn past the point and the squealer tab is making contact with the rotor. in either case it is time to have your brakes checked to make sure that you are still safe on the road.2. mdk68gto, ase certified m tech Says: i would check your transmission bracing.could be loose or need replacing. Tag: When i apply brakes and back up 96 grand prix se it makes a squeaking noise only time it does this what could?