What was found
ENG 1 HYD LOW PRESS LIGHT ON IN FLIGHT QUAN DROPED TO 0 FOUND HYD LEAK COMING FROM RETURN FILTER CASE & CLAM FOUND RETURN FILTER CASE BEND FOUND LEAK COMMING FROM THE FILTER CASE DRAIN ASSY. REPLACED CAS E AS PER AMM 29-11-61 PB401. PRECAUTIONARY REPLACED EDP ENG 1 AS PER AMM 29-11-11 PB401. RAN THE ENGINES FOR 10 MINS. NO LEAKS N OTED AT THIS TIME. ALL INDICATIONS NORMAL IN COCKPIT ADD EMP:U247191, U362339, U372867 ROTABLE PARTS CHANGE WAS INDICATED - TT # 1169014 SN OFF 1639 PUMP, HYD ENG D OFF 29-2910-9-0003 1639 ON 29-2910-9-0003 4006