What was found
(CAN) DURING CLIMB CREW REPORTED LOSS OF NR 2 HYD FLUID. NR 2 HYD ISO VALVE CAUTION LIGHT ILLUMINATED. NR 2 HYD QUANTITY GAUGE SHOWING DECLINE. AIRCRAFT RETURNED TO ORIGINATING AIRPORT, ALTERNATE GEAR EXTENSION USED, NORMAL LANDING. MAINTENANCE FOUND NR 2 HYD FLIGHT SPOILER VALVE CAP HAD SEPARATED, ALLOWING LOSS OF HYD FLUID. VARIOUS PARTS LOCATED IN THE NACELLE. CAP SHOULD BE SECURED TO VALVE BODY WITH 4 SCREW/STUDS, 3 STUDS REMAINED IN BODY, ONE MISSING. 2 HEADS STILL LOCKWIRED TOGETHER LOCATED IN NACELLE, REMAINING ATTACHMENT PARTS NOT LOCATED. VALVE REPLACED WITH SERVICEABLE UNIT, FUNCTION, LEAK CHECKED. AIRCRAFT RETURNED TO SERVICE.