Abstract: An apparatus is disclosed for lowering rectangular cored liners into a flue passage. The lowering apparatus includes a hydraulically actuated cross support cylinder releasably clamped between two opposite walls of the liner core. The cylinder ends have external, axially disposed rods each supporting a transverse pressure pad member. A piston, slidable in the cylinder, is actuated to extend one rod causing the pressure pad members to engage the opposite core walls and clamp the cross support cylinder in the liner core. The apparatus further includes a paired coextensive holding cable and flexible supply hose with one end of the cable connected by a stirrup-like sling arrangement to the pressure pad members. Uniformly spaced closed loops are formed in the cable at defined intervals for indicating to the user the arrival of the liner at a course depth and for temporarily securing the cable to a support.