Raymarine Autohelm ST7000 Installation Instructions Manual page 25

When the installation has been completed the
hydraulic pump may be operated by switching the
control unit to Auto and operating the + 10 deg.
and - 10 deg course change buttons. Greater
motor movements will be obtained if the rudder
gain is set to maximum.
The hydraulic steering system should be bled
according to the manufacturer's instructions. From
time to time during the bleeding process the drive
unit should be run in both directions to clear
trapped air from the pump and interconnecting
pipe work.
If the air is left in the system the steering will feel
spongy particularly when the wheel is rotated to
the hardover position. Trapped air will severely
impair correct operation of the autopilot and the
steering system and must be removed.
During the installation of the system it has not
been necessary to keep track of the connection
sense to the hydraulic steering circuit since
operating sense of the autopilot can be corrected
if necessary by reversing the polarity of the pump
drive motor connections.
Type 1 and Type 2 Installation
The pump should be mounted on a suitable
horizontal surface
20
All ports are tapped 1/4in B.S.P. Three 1/4in
B.S.P. to 1/4in N.P.T. adaptors are included to
convert to N.P.T. where required (Fig. 21). The
sealing washers supplied should be placed
between the fitting and the pump (Fig. 22).
Type CR Installation
The hydraulic power pack (Fig. 23) should be
bolted to a suitable horizontal surface. The service
ports are tapped to 1/4in B.S.P. and the reservoir
port is tapped to 3/8 B.S.P. Three N.P.T. adaptors
are included for conversion to N.P.T. where
required.