What was found
MIA - FLT 908 - DURING APPROACH TO MIA, NR 3 HYDRAULIC SYSTEM QUANTITY DROPPED TO ZERO. ACCOMPLISHED ALTERNATE LANDING GEAR EXTENSION AND AIRCRAFT LANDED MIA WITHOUT INCIDENT. REPLACED NR 3 ENGINE LOWER HYDRAULIC PUMP. PRECAUTIONARY REPLACED NR 3 ENGINE UPPER HYDRAULIC PUMP. REPLACED ALL NR 3 SYSTEM HYDRAULIC FILTERS. SYSTEM LEAK AND GROUND CHECKED NORMAL OPERATION. (M)