Abstract: In the centrifugal fan unit of an upright vacuum cleaner, the improvement of a metal liner to rehabilitate a worn out fan chamber or to improve the performance of a new centrifugal fan unit comprising a metal plate having an overall shape and size as the original fan chamber in its new condition and an assembly for mounting the liner in the chamber comprising a clamp fully manipulative from only one side of the vacuum cleaner base including a squeezable handle, a shaft passing fore and aft through the handle adapted for reciprocating movement relative to the handle, a bar on the shaft to allow it to pass through the base and reversibly abut the opposite side of the first chamber, a fan blank slidingly received on the shaft to abut the liner over substantially its full surface, a spring cooperative with the squeezable handle to draw the bar and fan blank together to squeeze the liner tightly against the base and a lever to release the clamp when the adhesive is set to hold the liner in position.