A piston pump assembly having a first pump comprising: a piston chamber forming member having a first chamber disposed about a first central axis and having a cylindrical side wall, an axially outer end of the first chamber being open downwardly, a piston forming element received in the first chamber axially slidable inwardly and outwardly therein between an outward extended position and an inward retracted position, the piston forming element having an axially extending stem, a first disc spanning radially between the stem and the first chamber side wall preventing fluid flow outwardly therepast, a continuous passageway (46,54) through the stem providing communication from inside the first chamber outwardly past the first disc through the outer end of the first chamber, the continuous passageway (46,54) opening at an outer opening, which is open to the first chamber and at an outlet outwardly of the first disc, wherein: the first chamber in normal use during or after operation to dispense fluid from the outlet including reciprocal sliding of the piston forming element relative the piston chamber forming member both air from the atmosphere and a liquid from a liquid reservoir become simultaneously disposed in the first chamber, the piston pump assembly including a foam generator disposed in the continuous passageway comprising a porous member for generating turbulence in fluid passing there through to generate foam when the air and the liquid pass there through simultaneously, and the piston pump assembly includes a liquid pump for providing the liquid from the reservoir via a liquid outlet into the first chamber, the liquid capable of foaming, and in operation of the first pump, fluid including foam between the first chamber and the outlet is drawn back into the first chamber via the continuous passageway (46, 54), and the continuous passageway (46,54) having as a first portion a central passageway and as a second portion an inlet passageway, the central passageway extending from the outlet to an inner opening, in normal use during or after operation to dispense fluid from the outlet including reciprocal sliding of the piston forming element relative the piston chamber forming member: (a) the inner opening disposed at a height above the outlet, (b) the inlet passageway extending from the inner opening open into the central passageway downwardly to the outer opening, (c) the outer opening disposed at a height below the inner opening, and (d) the outer opening disposed at a height above the outlet. a piston chamber forming member having a first chamber disposed about a first central axis and having a cylindrical side wall, an axially outer end of the first chamber being open downwardly, a piston forming element received in the first chamber axially slidable inwardly and outwardly therein between an outward extended position and an inward retracted position, the piston forming element having an axially extending stem, a first disc spanning radially between the stem and the first chamber side wall preventing fluid flow outwardly therepast, a continuous passageway (46,54) through the stem providing communication from inside the first chamber outwardly past the first disc through the outer end of the first chamber, the continuous passageway (46,54) opening at an outer opening, which is open to the first chamber and at an outlet outwardly of the first disc, the first chamber in normal use during or after operation to dispense fluid from the outlet including reciprocal sliding of the piston forming element relative the piston chamber forming member both air from the atmosphere and a liquid from a liquid reservoir become simultaneously disposed in the first chamber, the piston pump assembly including a foam generator disposed in the continuous passageway comprising a porous member for generating turbulence in fluid passing there through to generate foam when the air and the liquid pass there through simultaneously, and the piston pump assembly includes a liquid pump for providing the liquid from the reservoir via a liquid outlet into the first chamber, the piston pump assembly including a foam generator disposed in the continuous passageway comprising a porous member for generating turbulence in fluid passing there through to generate foam when the air and the liquid pass there through simultaneously, and the piston pump assembly includes a liquid pump for providing the liquid from the reservoir via a liquid outlet into the first chamber, the liquid capable of foaming, and in operation of the first pump, fluid including foam between the first chamber and the outlet is drawn back into the first chamber via the continuous passageway (46, 54), and the continuous passageway (46,54) having as a first portion a central passageway and as a second portion an inlet passageway, the central passageway extending from the outlet to an inner opening, the continuous passageway (46,54) having as a first portion a central passageway and as a second portion an inlet passageway, the central passageway extending from the outlet to an inner opening, (a) the inner opening disposed at a height above the outlet, (b) the inlet passageway extending from the inner opening open into the central passageway downwardly to the outer opening, (c) the outer opening disposed at a height below the inner opening, and (d) the outer opening disposed at a height above the outlet.