Overview

The Raymarine E12139 is a Type 0.5 hydraulic autopilot pump for 12 V systems, matched to hydraulic steering cylinders from 50 to 110 cc and used with the ACU-100. It is the pump section used where a Raymarine Evolution autopilot needs to drive an existing hydraulic steering circuit.

For buyers checking fit, the main numbers are straightforward: maximum intermittent pressure is 55 bar at 12 V, and peak flow rate with no load is 600 cc/min. This model is also suitable for Volvo D4/D6 sterndrive applications, and it is the matching Type 0.5 pump for EV-100 Power Pilot installations that use this drive size.

It is built for real installation conditions on board, with an IP67-rated motor, pilot-operated check valves, and protection for use in engine compartments. The pump can be used with balanced or unbalanced cylinders and with pressurized reservoir systems, which helps when matching it to an existing hydraulic layout.

Key features

• 12 V Type 0.5 hydraulic autopilot pump for Raymarine Evolution systems using the ACU-100
• Matched to hydraulic steering cylinder capacity from 50 to 110 cc, or 3.1 to 6.7 in3
• Maximum intermittent pressure of 55 bar at 12 V and peak no-load flow of 600 cc/min
• Pilot-operated check valves help stop the pump from being back-driven by helm input or rudder load
• IP67-rated motor and protection for use in engine compartments
• Works with balanced or unbalanced cylinders and with pressurized reservoir systems
• 1/4 in BSPP parallel-threaded ports for the hydraulic connections

Compatibility and fit

This pump is for boats that already have hydraulic steering and need a Type 0.5 autopilot drive sized for a smaller steering ram. The key checks before ordering are cylinder volume, 12 V supply, and ACU-100 compatibility. If your steering system falls outside the 50 to 110 cc range, a different pump size is usually required.

It is a sensible match for powerboats that are adding or restoring Raymarine Evolution autopilot control, including some Volvo D4/D6 sterndrive setups. On boats with mechanical steering, it can also be used alongside a secondary steering ram where the steering layout supports that arrangement.

Installation and setup

Mount the pump on a solid structure and keep hose runs as short as possible. The installation drawing shows four mounting holes for M6 bolts, with an overall body length of about 203 mm, a mounting width of 103 mm, and a height of 89 mm, which helps when checking space near the helm, transom locker, or engine room bulkhead.

The hydraulic ports are 1/4 in BSPP, so hose ends and adaptors need to match that thread. After plumbing and wiring, the steering circuit needs to be filled and bled carefully. Air left in the lines will reduce steering response and autopilot performance.

Maintenance and care

Routine checks are simple: inspect the pipework, electrical connections, mounting points, and joints for wear or leaks. The pump itself has no user-serviceable internal parts, but the motor can be removed from the pump head for replacement or inspection without letting fluid escape or pulling air into the hydraulic side.