HYDRAULIC STEERING SYSTEM.
See figure 6-1 for diagram of steering system.
a. The hydraulic steering systems use medium pressure hydraulic fluid to actuate cylinders which position the
rudders. Hydraulic fluid is supplied by the hydraulic pumps to the helm unit which is the principal metering and directional
controlling device. By directing hydraulic fluid to one side or the other of the cylinders they will extend or retract giving
the desired position to the rudders.
b. The helm unit and other valves control the direction and volume of flow of hydraulic fluid. The relief valve
protects the system by limiting hydraulic fluid pressure. The flow control valve (flow divider) limits the volume of fluid to
the valve at which this system is designed to work. The flow control valve (flow divider) divides the hydraulic fluid
supplied into two flows (2.5 gpm) to the helm unit, and the remainder returned to the storage tank.
The steering system is designed to be supplied by one pump. Using both pumps will
only cause a doubled by-pass flow resulting in excessive heating of hydraulic fluid.
The steering system pump discharge valves should be set with one valve open and
one valve closed.
The hydraulic fluid for this system should be a high grade fluid compounded for use in
a hydraulic system. Recommended hydraulic fluids are 2135 TH., MIL-L-17672, and
2075 TH., MIL-L-17672.