SeaStar HH5271 (and its modern version ) is a 1.7 cu. in. front-mount hydraulic helm pump used in outboard and inboard steering systems. While full exploded internal diagrams are often restricted to authorized service centers, the following report identifies key external components, common service parts, and technical specifications based on manufacturer documentation. West Marine Core Components & Exterior Parts
You can obtain the official diagram from several sources: Seastar Hh5271 Parts Diagram
"I need a Seastar HH5271 parts diagram to locate the and upper shaft seal . The diagram shows the helm body, input shaft, bypass valve (center), and end cap. The seal kit for this diagram is HS5157." SeaStar HH5271 (and its modern version ) is a 1