Boston Whaler 25 Guardian Series, Operation & Maintenance Manual

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4-4
Section 4 Boat Systems
Steering System
The steering system installed in your boat is a Teleflex
Sea Star II hydraulic system. This is a manually oper-
ated, closed-loop hydraulic system requiring no pumps
or electric motors. The system consists of the follow-
ing components:
• Steering wheel
• Sea Star II helm pump
• Teleflex hydraulic hoses
• Front-mount steering cylinders
• Sea Star HA-5430 fluid
The Sea Star II helm pump is an axial piston pump
specifically designed for manual steering. It has a
built-in lock valve to prevent the steering load of the
engines from feeding back to the boat operator. The
lock valve will not allow the outboards to move unless
the steering wheel is turned. The lock valve also con-
tains a pressure relief valve which provides over-pres-
sure protection for the mechanical components, the
hydraulic hoses, and the fittings.
When the steering wheel is turned clockwise , hydrau-
lic fluid is pumped out of the helm unit, into the star-
board hoses and then into the steering cylinders. As
the fluid is pumped into one side of the steering cylin-
ders, an equal volume of fluid is displaced from the
opposite side. The steering cylinder bodies move to
port. The cylinder bodies are connected directly to the
engine steering arms. The engine steering arms also
move to port and put the boat into a
starboard turn.
The fluid displaced from the steering cylinders returns
to the helm pump reservoir through the port hoses.
Turning the steering wheel counter-clockwise results
in a similar response, but in the opposite direction.
When no course correction is required, the lock valve
holds the outboard engines in place.
Return the steering wheel to the CENTERED position
when you turn the engines OFF .