What was found
AIRCRAFT WAS GROUNDED. MIA-KIN RETURNED TO MIA ACCOUNT SYSTEM A HYDRAULIC QUANTITY INDICATION. EMERGENCY WAS DECLARED. FLIGHT WAS NOT OVER WEIGHT AND LANDED WITHOUT FURTHER INCIDENT. LOSS OF SYSTEM "A" INFLIGHT. SYSTEM A EDP ILLUMINATED FOR DURATION OF FLIGHT (GREATER THAN 5 MINUTES). REPLACED LEFT ENGINE HYDRAULIC PUMP PER AMM 29-11-11. REPLACED ALL PRESSURE, RETURN, ENGINE AND EMDP FILTER/CASE. REPLACED EMDP IAW AMM 29-11-21. REPLACED PRESSURE AND RETURN HYDRAULIC LINES ON ENGINE. REPLACED CASE DRAIN LINE ON ENGINE IAW AMM 29-11-51. ACCOMPLISHED SYSTEM A HYDRAULIC FLUSH PER MCM 29-93-01. HYDRAULICS SYSTEM SERVICED. ACCOMPLISHED ENGINE RUN IAW AMM 71-00-00. LEAK CHECK AND OPERATIONS CHECKED OK ON THE GROUND.