O-ring installation tool and method of installing an O-ring in an inner diameter

Tool for installing O-rings in an inner diameter of a structure includes a plurality of held in a spaced, fixed parallel relationship to one another. A plurality of guide surfaces are secured with and disposed between the plates. A selectively-actuable finger actuator is disposed to move a plurality of fingers generally radially between the plurality of plates. Each of the plates includes a slot, and a loading pin is configured to be received within the slots. When at least one O-ring is disposed about a plurality of guide surfaces proximal the periphery of the plates, and the loading pin is moved within the slots, the loading pin pulls a loop of the O-rings toward the plate axis. When the loading pin is removed, the finger actuator may be actuated to move the fingers in the generally radial direction to move the at least one O-ring radially outward from the plates.