What was found
DURING CRUISE AT FL410, CREW RECEIVED HYD LEVEL LOW RT LIGHT FOLLOWED BY AUX HYD PUMP ON LIGHT. CHECKLIST FOLLOWED, EMER DECLARED & UNSCHEDULED LANDING PERFORMED WITHOUT INCIDENT. EVALUATION FOUND EVIDENCE OF LT MAIN GEAR ACTUATOR LEAKING FROM HOUSING TO PISTON SEAL. R & R LT MAIN GEAR ACTUATOR, OFF PN 26300-000-05, SN IL-004. ADDITIONAL PARTS REPLACED DUE TO EXCESSIVE HYD FLUID LOSS, RT MAIN HYD PUMP, RT HYD FILTERS & RT HYD PRESS SWITCH.