What was found
DURING REMOVAL OF ROTOR BRAKE CALIPER ASSEMBLIES, FOUND GUIDE HOLES ON PAD ASSY AND GUIDE BOLTS WORN. BOLT, PN D0166-1, WORN IN EXCESS OF 50 PERCENT OF BOLT DIAMETER. PAD ASSY, PN D0163-1, GUIDE HOLES WORN IN EXCESS OF 65 PERCENT OF WALL THICKNESS. POSSIBLE CAUSE OF PREMATURE WEAR MAY BE FROM EXCESSIVE VIBRATION AND SMALL AREA OF CONTACT AT BOLT AND PAD ASSY GUIDE HOLES. SUBMITTER RECOMMENDED INSPECTION OF BOLTS AND PAD ASSEMBLIES EVERY 600 HOURS.