Overview

The Simrad 000-15446-002 is a 12V reversible hydraulic gear pump used as the drive unit in a Simrad autopilot system for balanced hydraulic steering cylinders. It moves 3.0 L per minute (183 cu in/min) and matches cylinder displacements from 290 to 960 cc (17.7 to 58.5 cu in), which covers many mid to larger hydraulic steering rams.

This pump is used with NAC-3 or AC42 autopilot computers and supports SteadySteer. On most installations it is placed below the helm pump and plumbed into the two main steering lines, with the center port tied into the steering reservoir balance line.

It is a good match for boats up to about 70 ft that run a 12V electrical system and need a 3.0 LPM pump size to keep hard-over steering time in a normal range.

Key features

• 12V reversible hydraulic gear pump with nominal flow of 3.0 L/min (183 cu in/min)
• Works with balanced cylinders in the 290 to 960 cc (17.7 to 58.5 cu in) range
• O-Ring Boss ports with 1/2-20 SAE (-05 ORB) female threads on the pump body
• Includes three straight adapters: -05 ORB to 9/16-24 (3/8 tube style) for common hose and tube ends
• Integral lock valves help hold rudder load when the pump is not running
• Typical current draw 10 to 20 A, with peak around 30 A under load for wiring and breaker planning
• Overall length about 214 mm for mounting and service clearance planning

Compatibility and fit

This pump is intended to be driven by Simrad NAC-3 or AC42 course computers and is sized for hydraulic steering systems that use a balanced cylinder. Confirm your steering cylinder displacement falls within 290 to 960 cc, and verify your autopilot computer and boat supply are 12V.

Hydraulic connections are ORB style, so match your hose ends or adapters to -05 ORB on the pump side. The two outer ports connect into the port and starboard steering lines, and the middle port connects to the steering reservoir balance line.

Installation and setup

Mount the pump lower than the helm pump so it stays primed, and route the reservoir hose upward to the helm reservoir connection without dips that can trap air. The pump can be mounted in any orientation as long as the plumbing is supported and protected from chafe.

When installing ORB fittings, keep threads clean, lubricate the O-ring with hydraulic oil, and tighten to the specified torque. After plumbing and wiring are complete, bleed the steering system thoroughly until steering response feels firm and consistent.

Electrical and system integration

Wire the pump directly to the autopilot course computer pump outputs, using cable sized for voltage drop and the pump load. A minimum of AWG 8 (10 mm2) is commonly used for this 12V pump class, depending on run length and installation standards.

Keep all connections above bilge water where possible, support cables to avoid vibration fatigue, and protect the circuit with the correct breaker or fuse as specified by your autopilot computer installation requirements.

What’s included

• PUMP-4 MKII 12V reversible hydraulic pump
• 3 x -05 ORB to 9/16-24 straight adapter fittings

Maintenance and care

Periodically check all hydraulic fittings for seepage, inspect hoses for chafe, and keep the steering reservoir topped up with the correct hydraulic fluid. If the pump gets louder over time or steering feels spongy, recheck for air in the lines and bleed the system again.