What was found
NOTICED A SLOW LEAK IN HYD QTY NR 3 RESERVOIR ,WITH A LEVEL 1 "HYD 3 ELEV OFF" ALERT. CONFIGERED AND GEAR DOWN EARLY THE GTY CONTINUED TO DECREASE WITH EVENTUALLY GOING TO 0GALLIONS QTY AND LEVEL 2 "HYD 3 FAIL" ALERT. ALSO NR 1 HYD SYSTEM LEFT EDP APPEARS DISCOLORED AND AMBER AND THE RIGHTEDP DID NOT CHANGE FROM ARM TO ON. FOUND BLOWN O-RING ON AFT PUMP PRESSURE ACTUATED SWITCH ON TOP ON FILTER MANIFOLD. ALSO FOUND DPI EXTENDED FOR UPPER RIGHT FILTER. REMOVED AND REPLACED HYD PUMP LOW PRESSURE SWITCH IAW AMM 29-12-34-2-2. LEAK AND OPS CHECK. AMM 29-12-34-2-2 AND 29-11-20-5