Abstract: A pump dispenser for liquid products includes a pump chamber having a cylinder, and a piston slidable within the cylinder with an outlet passage extending through the piston. A spring within the chamber urges the piston to an extended position. An inlet opening is disposed at an end of the chamber for receiving product to be dispensed. An inlet check valve is positioned at the inlet opening to permit entry of product into the chamber as the piston is extended by the spring, but to prevent exit of product from the chamber through the inlet opening as the piston is depressed against the spring. An outlet check valve is carried by the piston within the outlet passage to permit discharge of product from the chamber through the outlet passage as the piston is depressed against the spring.