On my newly acquired 61 apache the previous owner installed a new master cylinder but never bled the brakes. I bled all the brakes and adjusted all the brakes till they started to grab a little. (I already dismantled the brakes and freed up the rusted adjusters and lubed the backing plates.)When I apply the brakes the right rear tire skids. When I spin the wheels when they are off the ground they all seem to have equal grab. Any suggestions?