The invention is a hydrogen generator including a pump for pumping a liquid from a reservoir to a reaction area, where the liquid reacts to produce hydrogen gas, and a fuel cell system including the hydrogen generator and a fuel cell stack. The pump is a diaphragm pump with mechanically operated liquid inlet and outlet valves that are opened by cam-operated pushrods, and the pushrods are isolated from the liquid flowpath through the pump by diaphragms. All valves in the liquid flow path between the liquid reservoir and the reaction area are mechanically operated valves.
