There is disclosed a machine (1, fig 1) for dispensing a flowable substance, which in one embodiment comprises a manifold 5, a first piston 4a arranged for reciprocating movement within a respective first cylinder 24a, a second piston 4b arranged for reciprocating movement within a respective second cylinder 24b, first and second supply chambers 27a and b, for holding respective volumes of a said flowable substance, and a moveable valve 8 member provided within said manifold. The manifold defines or is fluidly connected to an outlet nozzle and is fluidly connected to said cylinders and to the supply chambers. The valve member is moveable between: i) a first position in which it fluidly connects the first cylinder to the outlet nozzle, and fluidly connects to the second cylinder to the second supply chamber, and ii) a second position in which it fluidly connects the second cylinder to the outlet nozzle and fluidly connects the first cylinder to said the supply chamber.
