What was found
DURING THE AFTER TAKEOFF CHECKLIST, CREW NOTICED HYD 2 PRESSURE AT 1900 PSI. PRESSURE REMAINED AT 1900 PSI FOR 15-20 MINUTES. PRESSURE THEN FELL TO 1800 PSI. RAN QRH FOR HYD 2 LOW PRESSURE. PRESSURE INCREASED TO 2800 PSI WITH QTY AT 85 PERCENT. PRESSURE & QTY REMAINED CONSISTENT FOR 5 - 10 MINUTES. HYD 2 B STARTED MAKING GROWLING NOISES AND QTY WENT TO 100 PERCENT AND PRESSURE WENT TO 0 PSI. COMPLIED WITH EDP 2 QRH. LANDED. BMTS 4433, EDP2 WAS AT 0 PSI FOR 30 MINUTES. REMOVED HYD SYS NR 2 PRESSRUE MANIFOLD FILTER BECAUSE DPI WAS POPPED. FILTER CONTAINS DEBRIS. REPLACED EDP NR 2 IAW AMM 29-11-01 AND COMPLIED WITH FILTER R & R SUPPLEMENT 06-029C. SYSTEM TESTED, LEAKED CHECKED GOOD. REPLACED ALL NR 2 HYDRAULIC SYSTEM FILTERS IAW SUP 06-029C.