A lubrication pump includes a housing defining a bore, an adjustable cylinder sleeve within the bore, and a piston slidably movable within the bore along a longitudinal axis of the bore. A connector may be drivingly interposed between a cam and the piston for driving the piston in reciprocating axial motion. The connector may have a coupling for engaging the piston, which may enable rotational engagement between the connector and the piston. The connector may have a roller for bearing engagement with the cam, which may enable the connector to rotate about the longitudinal axis relative to the housing as the connector moves axially within the bore. The cam may be laterally displaceable relative to the connector. The cylinder sleeve may be adjustable relative to the piston for varying lubricant fluid output flow. The cylinder sleeve and corresponding piston may be interchangeably disposed in the housing.