Overview

The Simrad 000-11770-002 is a 12V DC reversible hydraulic pump used as the drive unit for autopilot steering on hydraulic systems. Nominal flow is 0.8 lpm, and it is listed as compatible with SeaStar manual helm pumps up to 14 cu in.

The pump tees into the steering lines and pushes fluid either direction when the autopilot commands a turn. Integral lock valves help hold steering load when the pump is not running, and the three -05 ORB ports are supplied with three ORB-5 to 9/16 UNF fittings for common hose end connections.

Key features

• 12V DC reversible gear pump with nominal flow of 0.8 lpm
• Direction changes by reversing motor polarity, so no external direction-control valve is required
• Integral lock valves help hold steering load when the pump is not running
• For balanced hydraulic cylinders only
• Listed as compatible with SeaStar manual helm pumps up to 14 cu in
• Three pump ports are -05 ORB, with 3 x ORB-5 to 9/16 UNF fittings included for hose hookup
• Overall length about 168 mm for mounting-space planning

Installation and setup

Plan the mounting location before you cut into the steering lines. The pump should sit lower than the helm pump, and the balance line back to the helm reservoir should run upward with no dips where air can collect. The unit can be mounted in any orientation, but leave room to access the fittings for inspection and re-tightening after the first run.

The two outer ports connect to the main steering lines (typically using tee fittings). The center port is the balance line that returns to the helm reservoir or a dedicated steering reservoir, depending on how your system is set up.

After plumbing, bleed the steering circuit thoroughly. Any air left in the system can make steering feel soft and can cause noisy pump operation and poor autopilot response.

Electrical and system integration

This pump is for 12V DC systems. Typical current draw is 4 to 7 A with peaks up to 11 A at 50 bar, so cable size matters on longer runs to keep voltage drop down. A minimum of 12 AWG (4.0 mm2) conductors is a common baseline when routing from the course computer to the pump in a small-boat install.

The autopilot drives the pump by reversing polarity on the motor leads. Keep connections clean, strain-relieved, and protected from bilge water and spray, and follow the wiring diagram for your specific autopilot controller.

Compatibility and fit

Confirm your steering uses a balanced cylinder before selecting this pump. Also verify that your hose ends and steering plumbing match the included -05 ORB to 9/16 UNF fittings, or plan the correct adapters so you are not stuck mid-install.

If you have multiple helms or a separate pressurized reservoir, keep the balance line routing simple and direct, and use a reservoir connection associated with the primary helm whenever possible.

Use on board

This pump is commonly used on outboard-powered boats with hydraulic steering where an autopilot needs a compact hydraulic drive for holding course while trolling, running between spots, or making longer offshore transits. It fits best when you are staying on a 12V system and your steering hardware falls within the balanced-cylinder requirement.

What’s included

• PUMP-1 MKII hydraulic pump (12V)
• 3 x ORB-5 to 9/16 UNF fittings