What was found
HYD SYS QTY IND 23% AT TAXI IN. NR 1 EDP LOW PRESS LIGHT ILLUMINATED. PER QRH TURNED OFF PUMP. QTY & PRESS GOOD THRU 40000 FT. ON APPROACH AFTER GEAR SELECTED DOWN, NR 1 SYS HYD QTY HAD DEPLETED. REMOVED NR 1 HYD PUMP IAW AMM 29-11-11-000-801-001STEP 2A-F(7). REMOVED EDP CASE DRAIN FILTER MOD IAW AMM 29-11-51 STEP 4 & REMOVED CASE DRAIN FILTER ELEMENT IAW AMM 29-11-51 STEP 2. EXAMINED NR 1 EDP CASE DRAIN LINE, CASE DRAIN HOSE, QUICK DISCONNECT, FILTER MOD & FILTER FOR DEBRIS OR BLOCKAGE & FOUND TO BE CLEAN IAW AMM 29-11-11 STEP 3F(12). ON REMOVAL OF NR 1 EDP, FOUND METAL & PLASTIC DEBRIS COMING OUT OF CASE DRAIN PORT. REPLACED NR 1 EDP CASE DRAIN FILTER MOD CHK VALVE IAW AMM 29-11-51 STEP 4F(4)(A) & STEP 5F(1)(D)(F)(6). REMOVED A SYS HYD PUMP, R & R NR 1 ENG CASE DRAIN FILTER MOD CHK VALVE. R & R EDP CASE DRAIN FILTER, REMOVED A SYS HYD RETURN FILTER, A SYS PRESS PTU. ALL FILTERS INSTALLATION AND TEST IAW AMM 29-11-41, AMM 29-11-51, AMM 29-11-61, AMM 29-11-71, AMM 29-11-11, & 29-22-21. LEAK CHECKED GOOD. ORIGINAL SUB DATE: 8/4/2021