6021-21 Random Orbital Sander Pad Brake Retrofit Pulley
requires modification to existing pad brake and belt from Porter Cable 333, available online.
This pulley fits between sanding pad and pad mounting plate. After attaching this one and the fixed pulley, install belt over both pulleys. Cut off any remaining original brake fins for clearance. Reinstall sanding pad and check for proper operation. Belt should provide brake action while allowing the pad to rotate slowly when engaged with work piece.