What was found
ON TAKEOFF ROLL, BRAKES APPEARED TO BE DRAGGING. CREW DECIDED TO ABORT TAKEOFF W/O INCIDENT AND TAXIED BACK TO GATE. MAINT JACKED AC AND CHECKED BRAKES. BRAKES APPEARED TO BE DRAGGING AND NOT RELEASING ALL THE WAY. THESE ARE UNMODIFIED BRAKES (W/O STAINLESS STEEL SLEEVES) CHANGED ALL BRAKES AND THE AC IS BACK ON FLIGHT LINE. SUSPECT THAT REASON FOR BRAKES DRAGGING ARE UNMODIFIED BRAKES. THESE WILL BE SENT OUT FOR O/H AND MODIFICATION. THIS PROCESS IS RECOMMENDED BY MFG FOR CORROSION IN THE PUCK AREA. IN THE PROCESS OF CHANGING ALL OF THE BRAKES FLEET WIDE TO THE MODIFIED BRAKES TO HELP ELIMINATE THIS PROBLEM.