I am having trouble getting my customers trucks brakes working. I removed the brake assy off top of the drive motor and tore it down. I replaced the o-rings because it was leaking. After I assembled it, I bled the brakes. the assembly doesn't move and the brakes are locked. Is there some special way to do this? Please help. Thanks, Jim p.s.- I dropped a spacer into the drive motor. Is it easier to remove the drive motor and tip it over or remove the brush holder and fish it out? Any suggestions? Why aren't they made out of metal, so I could use a magnet?