What was found
ON CLIMB OUT WE WERE UNABLE TO RAISE THE GEAR HANDLE. NO EICAS OR OTHER MESSAGES OR ABNORMAL INDICATIONS. EMERGENCY DECLARED. PERFORMED FULL NLG STRUT SERVICING, OPC LEAK CHECK GOOD, IAW AMM 12-12-09. PERFORMED LANDING GEAR EXT/RET OPC, OPC GOOD, IAW AMM 32-33-00.