Hydraulic Considerations
NOTICE
This pump must not be installed with a steering system that has an unvented reservoir, because it will damage
the pump. Before installing the pump, you must verify that the vessel steering has a vented reservoir. Typically,
the vent hole is in the filler cap of the highest helm. If you are not clear as to whether the steering system is
vented, you should check with the manufacturer of the helm or the reservoir to verify.
Do not attempt to use the autopilot to steer the boat until you bleed all air from each part of the hydraulic
system.
When adding hydraulic line to the system, use only hose that is -4 [6 mm (
1
/
4
in.) ID] or larger with machine-
crimped or field-replaceable fittings that have a minimum rating of 1000 lbf/in² (6,895 kPa).
You must not use thread seal tape, such as Teflon
®
tape, or thread putty on any hydraulic fitting in this system.
Small debris from thread seal tape or thread putty can enter the hydraulic system, become stuck in valves, and
render the autopilot or steering system inoperable. Using thread seal tape or thread putty on any hydraulic
fitting in this system voids your warranty.
Use caution when applying liquid thread sealant to avoid damage to the hydraulic system or to the autopilot
system.
Before you connect the pump to the hydraulic lines, you should consult the hydraulic-layout diagrams to help
determine how to best install the pump in the hydraulic system of the boat (
).
When planning the hydraulic layout and making all hydraulic connections, consider the following:
• The pump must be reconfigured if the boat is equipped with an unbalanced steering cylinder (
Pump for an Unbalanced Cylinder, page 11
).
• The size and thread types for the hydraulic ports on the pump are listed in the specifications (
).
• You must use -4 [6 mm (
1
/
4
in.) ID] or larger hoses for all hydraulic connections, including the return line.
• For installations with larger steering cylinders or those requiring higher fluid pressure, you should install the
pump as close to the cylinder as possible, so that preferably no more than 3 m (10 ft.) of hydraulic hose
connects the pump to the cylinder.
• You should use T-connectors (not included) to connect the hydraulic lines to the pump.
• You should install shut-off valves (not included) in the hydraulic lines between the pump manifold and T-
connectors to allow for easy pump isolation and removal.
• For hydraulic fittings with an O-ring, such as ORB and ORFS fittings, you should not use thread sealant.
• For hydraulic fittings without an O-ring, you should use a liquid thread sealant, such as Loctite 567.
• When using liquid thread sealant, you must follow the instructions regarding the cure time, for example,
Loctite 567 cures after four hours. If the thread sealant is not properly cured per the manufacturer's
instructions, the high pressure in the hydraulic lines may push the sealant out of the threads and create a
leak.
• When disconnecting a connector sealed with liquid sealant, you must take care to keep any slivers or other
debris from the cured sealant from entering the hydraulic system.
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