A method for assembling a damper with a device includes inserting a floating piston into a cartridge, filling a region of the cartridge with oil, inserting a piston-rod assembly into the cartridge, inserting a rod guide into the cartridge, coupling a damper tube to the cartridge, supplying a gas into the damper tube via a first end of the damper tube, transferring the floating piston, the piston-rod assembly, the rod guide, and the oil from the cartridge to the damper tube through the first end of the damper tube, and securing the rod guide to the damper tube.