A foldable vehicle seat is constructed such that when the seat is placed in a passenger area and that a seat cushion is tipped up from a seating position, a forward-inclination stopper stops once the seat cushion at an upright position by abutting on a lock plate. The first liquid supply unit supplies a transfer liquid to a first cylinder. The tubular member has a coupling at its end opposite to the end carrying the expandable element to which a hose is connected in order to alternately supply pressurized water to the element or to the conduit. The compliant pin sections include an upstanding, rigidifying section to rigidify the compliant pin portion during the insertion of the electrical connector and the plurality of compliant pin portions into the printed circuit board. A substantial amount of plumbing is self contained in a single body minimizing the need for additional components or complexity.