What was found
DURING A SCHEDULED MAINTENANCE VISIT WHILE PERFORMING A (D) LEVEL INSPECTION A BRAKE RETURN LINE WAS FOUND TO BE CHAFING FROM A SCREW THAT SECURES THE CENTER COCKPIT TO CABIN FLOORBOARD. INSPECTION AND REPAIR OF THIS AREA IS OUTLINED IN MFG SB 53-3511. THE CHAFED PORTION OF THE BRAKE LINE (P/N 128-580101-1) WAS CUT OUT AND A NEW SECTION OF BRAKE LINE WAS INSTALLED USING A D10036-06 UNION.. THE BRAKE SYSTEM WAS BLED AND LEAK CHECKS WERE GOOD. THE SCREW HOLE THAT ALLOWED THE CHAFING WAS RELOCATED. ALL WORK WAS COMPLETED IAW SB 53-3511.