Abstract: A rear milking cluster hose support arm for supporting a milking cluster hose in an existing milking system where milking is done from a rear of a cow includes a rubber bumper for supporting an existing cluster hose and a rectilinear rod. The apparatus further includes a rod holder and a selectively adjusting mechanism with a coupling nut, an air hose, a tee union adapter, and a flattened lever. A predetermined oscillating air pressure level is introduced into the cylinder from the existing air supply source to thereby raise and lower the coupling nut and articulate the lever about the rod to thereby adjust the position of the rod and the rubber bumper respectively during non-operating conditions.