What was found
AIRCRAFT WAS GROUNDED: AN EMERGENCY WAS DECLARED DUE TO: LEFT HYDRAULIC SYSTEM-A SHOWED QTY 67% AND DROPPING SLOWLY DURING CRUISE. AIRCRAFT DIVERTED TO AND LANDED SAFELY AT MIA. ON ARRIVAL TO THE A/C, OBSERVED THAT SYSTEM A AND B HYDRAULIC RESERVOIRS ARE WITHIN OPERATIONAL QUANTITY LIMITS, PER AMM 12-12-00-610-801. SYSTEM-A AT 95% SYSTEM-B AT 98%, ACCOMPLISHED HYDRAULIC SYSTEM LEAK CHECK, PER AMM 29-00-00-790-801 NO LEAKS NOTED AT THIS TIME OF INSPECTION. PER BOEING FLEET TEAM DIGEST 737NG-FTD-29-01003 NO FURTHER ACTION REQUIRED AS LONG AS THE HYDRAULIC RESERVOIR LEVELS RETURN TO NORMAL ON THE GROUND AT AMBIENT TEMPERATURE.