Abstract: A dispensing pump includes first and second sleeve assemblies. Each sleeve assembly includes a rotary valve having an input and output position and a longitudinally displaceable piston that moves between a first position abutting the valve and a second position displaced from the valve. The sleeve connects to a manifold with input and output passages that align with input and output apertures in the sleeve. Withdrawing the piston with the input port of the valve aligned with the input aperture draws material into the sleeve. Moving the piston toward the valve in the output position with the output port aligned with the output passage displaces material from the manifold.