TM10-3930-660-34 10-3 DISC BRAKE ASSEMBLY - REPLACE/REPAIR (Cont’d) 2 INSPECT HOUSING (6) a    Inspect piston bores and ring grooves in housing for scratches and rust Use emery cloth to remove small scratches and rust Discard housing if there are large scratches or amounts of rust b    Measure inner diameter of piston bores in housing (6) Discard housing if inner diameter of bore s more than 3 003 inch ASSEMBLY WARNING Use only specified parts when assembling the disc brake Do not mix parts from other disc brakes If installing the wrong parts, the disc brake will not operate correctly and could result in severe personal injury and equipment damage NOTE Wipe all sealing surfaces on disc brake clean and dry Apply film of clean hydraulic oil to all seals, pistons, and bores as parts are installed 1 INSTALL SEALS IN HOUSING (2) a Install new backup ring (14) and new O-ring (13) in middle groove of each bore The backup ring (14) is installed toward the lining side of housing (6) The O-ring (13) is installed towards the outside of the housing b Install four dust seals (12) in inner groove of housing bore 10-6