On June 16, 2013, about 1140 Pacific daylight time (PDT), a Cessna T210L, N94086, landed gear-up at Fresno Yosemite International Airport, Fresno, California. The owner/pilot was operating the airplane under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The private pilot and one passenger were not injured; the airplane sustained substantial damage. The local personal flight departed Fowler, California. Visual meteorological conditions prevailed, and no flight plan had been filed. The pilot reported that he was unable to fully retract the landing gear after takeoff. He was unable to correct the situation and attempted to manually extend the landing gear by use of the manual extension procedures, which were unsuccessful. The pilot elected to divert to the accident airport, and land with the landing gear partially extended. During the landing, the airplane sustained substantial damage to the left wing, left aileron, left horizontal stabilizer, and elevator. During post accident examination the landing gear systems were intact except for the lack of hydraulic fluid. Once the system was filled with hydraulic fluid the landing gear would not extend using the electric pump. Use of the manual extension system did not extend the gear. A leak in the nose landing gear actuator rod seal was observed. Maintenance personnel related that the fluid leak prevented the hydraulic system from building up enough pressure to extend/retract and lock the gear. Examination of the underside of the airplane found a film of sticky fluid from the nose landing gear wheel well to the tail of the airplane. In addition, drops of hydraulic fluid were found on several antennas on the bottom of the airplane. The nose gear actuator has no requirement for overhaul or reseal and is considered "on condition."