Abstract: Apparatus for wet cleaning carpet is disclosed of the type which utilizes a wet-dry tank unit (C) having a vacuum hose (56) connected to the vacuum tank and a vacuum head (52). The apparatus includes a portable base (A) for moving the apparatus over the floor having a socket (12) formed in the portable base. A cleaning solution tank (B) for containing a cleaning solution includes a lower attachment collar (D) which fits in the socket (12). A liquid pump (40) is carried in a pump housing (30) formed in solution tank (B). An upper attachment recess (66) formed in solution tank (B) receives a base (74) of the vacuum unit (C). The portable base (A), solution tank (B), and vacuum unit (C) are snugly fitted together by means of a deep socket (12) and recess (66) to provide an integrally assembled structure. By housing the pump (40) low to the floor in the portable base (A), a low center of gravity and stable weight distribution is provided.