As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING APPROACH, UPON EXTENDING LANDING GEAR THERE WERE EXTREMELY LOUD GEAR GRINDING NOISES, IT TOOK APPROX 15 SECONDS FOR THE GEAR TO FULLY EXTEND. THE GEAR MOTOR SEEMED TO BE RUNNING IN INTERMITTENT SEGMENTS, THE RT MAIN EXTENDED FIRST FOLLOWED BY THE LT MAIN AND NOSE. FOUND SUPPLY BLEED AIR TUBE BROKEN AT AIR FILTER CHECK VALVE. REPLACED TUBE ASSY. OPS CHECK GOOD.