What was found
DEPARTED, SHORTLY AFTER LEVELING OFF AT FL 250, HYD FLUID LOW, CAUTION ANNUNCIATOR ILLUMINATED. FOLLOWED CHECKLIST & CONTINUED TO DESTINATION. DURING NEXT SEVERAL MINUTES CREW HEARD GEAR PUMP MOTOR CYCLING FOLLOWED BY LG RELAY CB EXTENDED. DURING APPROACH LG WOULD NOT EXTEND. AN EMER WAS DECLARED & A MANUAL LG EXTENSION WAS PERFORMED IAW CHECKLIST. CONFIRMED 3 GREEN LG INDICATION. LANDING WAS UNEVENTFUL. MX TROUBLE SHOT THE DISCREPANCY TO A DEFECTIVE LG EXTENSION & RETRACTION ACCUMULATOR. GEAR ACCUMULATOR WAS REPLACED & ACFT WAS RETURNED TO SERVICE.