Patent ID: 8812201

Claim:
A hydraulic control system for an automatic transmission that is adapted to vary a torque inputted thereto according to a speed ratio and output the varied torque from an output member to a driving wheel, and to vary a transmission torque capacity by delivering or draining hydraulic fluid to/from an actuator of a transmission member, the hydraulic control system comprising: a discharging device configured to discharge compressible gas entrained in the hydraulic fluid in the actuator; another member interposed between the output member and the driving wheel, the another member being rotated by a torque transmitted from the output member; an interrupting device configured to disconnect the output member from said the another member; and a controller configured to: (1) determine whether an entrainment of the compressible gas in the hydraulic fluid has occurred; (2) disconnect the output member from the another member via the interrupting device in a case that the controller determines that the compressible gas is entrained in the hydraulic fluid; and (3) cause the entrained compressible gas to be removed from the hydraulic fluid and discharged through the discharging device by causing the actuator to rotate with the transmission member under the condition that the output member has disconnected from the another member.