"This field manual (FM) serves as a guide for personnel who operate and maintain military equipment using hydraulic-powered control systems. It includes general information covering basic hydraulics and describes the properties and characteristics of fluids and several types of pumps, motors, valves, and controls. This manual also deals with piping, tubing, and hoses used to convey fluid under pressure. It describes the functions and types of reservoirs, strainers, filters, and accumulators. It discusses the purposes and types of seals and packings used in fluid power systems."-From the Preface.