A method and apparatus for setting an inner wellhead member in a subsea wellhead housing includes connecting an inner wellhead member to a running tool and running the running tool and wellhead member through a tubular member to a wellhead housing. A plurality of pistons urge fluid through a closed-loop hydraulic system. That fluid actuates a locking mechanism to lock the inner wellhead member into the wellhead housing, and also actuates a release mechanism to release the running tool from the inner wellhead member. The pistons are moved from one position to another in response to fluid pressure from the running string to which the running tool is connected, fluid pressure from the tubular member in which the running tool is located, or in response to fluid in the closed-loop hydraulic system that is being moved in response to the other one of the pistons.