The Portable Automatic Milker Detacher for use in stanchion barns is powered by the pipeline vacuum, is operated by a cable system, and hangs from the pipeline. Weighing only about 6½ pounds (including the pulsator), it can be easily carried from cow to cow. One end of the cable fastens to the milker claw; the other end wraps around a pulley on the end of a pneumatic cylinder. As the cylinder extends, the cable is lengthened; as it retracts, the cable is pulled in. The cable is lengthened to put the milker on the cow, causing the cylinder to extend. When the cow is finished milking, a sensor detects the decreased milk flow and signals the vacuum to shut off, causing the cylinder to retract and the cable to remove the milker.