Abstract: A high-pressure, plunger-type liquid pump including a liquid manifold that includes a plunger chamber in the form of an axial cylindrical bore portion for slidably receiving a pressurizing plunger, and that also includes a valve chamber coaxial with the plunger chamber and in communication therewith for removably receiving a cartridge-type flow control valve. The liquid manifold includes a closure plug to close the valve chamber. The cartridge-type valve is slidably received in the valve chamber for enabling removal of the cartridge-type valve from the liquid manifold without the need for separating the liquid manifold from the pump drive housing. The cartridge-type valve is of a structure that includes in-line, axially spaced suction and discharge valves that are each spring biased into closed positions.