Deactivation roller hydraulic valve lifter

A deactivation hydraulic valve lifter includes an elongate lifter body having a substantially cylindrical inner wall. The inner wall defines at least one annular pin chamber therein. The lifter body has a first end configured for engaging a cam of an engine. An elongate pin housing includes a substantially cylindrical pin housing wall and pin housing bottom. The pin housing wall includes an inner surface and an outer surface. The pin housing bottom defines a radially directed pin bore therethrough. The pin housing is concentrically disposed within the inner wall of the lifter body such that the outer surface of the pin housing wall is adjacent to at least a portion of the inner wall of the lifter body. A plunger having a substantially cylindrical plunger wall with an inner surface and an outer surface is concentrically disposed within the pin housing such that the outer surface of the plunger wall is adjacent to at least a portion of the inner surface of the pin housing wall. A deactivation pin assembly is disposed within the pin bore and includes two pin members. The pin members are biased radially outward relative to each other. A portion of each pin member is disposed within the annular pin chamber to thereby couple the lifter body to the pin housing. The pin members are configured for moving toward each other when the pin chamber is pressurized, thereby retracting the pin members from within the annular pin chamber and decoupling the lifter body from the pin housing.