Abstract: A jam-proof, high pressure, check-valved input fitting comprising a travel limiting cage for controlling its internal valve spring system to prevent spring bending and cylinderization. A terminal engageably by a high pressure grease source leads to an internal tubular flow passageway comprising axially aligned inlets and outlets separated by a valve seat. A ball valve which contacts the valve seat to control fluid flow is biased by a spring coaxially seated within the upwardly projecting castellated end of the cage. The cage includes symmetrical, radially spaced apart legs and a plurality of relief orifices in the form of radially spaced apart slots defined between adjacent feet. The relief orifices establish fluid flow communication between the outside of the cage and its interior. When compressed downwardly against yieldable spring pressure, the ball is stopped by the cage before the spring can cylinderize.