A hydraulic hammer includes a powercell housing that defines a hydraulic inlet and a hydraulic outlet. A work tool is partially received in, and movable with respect to, the powercell housing. A switching spool valve member is positioned in the powercell housing and is movable between a first position and a second position, and includes a control hydraulic surface. A sleeve/liner assembly is positioned in the powercell housing and defines a centerline. A piston with a plurality of hydraulic surfaces is positioned in the sleeve/liner assembly and is movable along the centerline between positions in and out of contact with the work tool. The control hydraulic surface of the switching spool valve member is exposed to fluid pressure in a switching passage, which includes a segment defined by the sleeve/liner assembly.