I was checking my rear brakes and i noticed that the peice of metal that locks the adjustment screw keeps poping out and not holding it in place. i have reset it twice and it makes the car feel like it is brand new no pulling when braking and it dont pull when crusing down the road either it stays that way for about 3 or 4 heavy stops mabe a few more if i baby it. But then it pops back to all loose and crap. any way to fix this?