Reversing Piston Pump | Octopus Autopilot Drive Systems

Reversing Piston Pump

  • RELIABLE - Patented piston pump technology with only three moving parts

  • TWICE THE POWER - Delivers over twice the hydraulic output per watt of input

  • HALF THE POWER CONSUMPTION - Accurate ram positioning means fewer course corrections

  • ADJUSTABLE FLOW RATE - Configure performance to suit your vessel

  • EASY SERVICING - Shut off valves allow removal without draining steering system


The unique Octopus piston pump delivers over twice the hydraulic output per watt of input than a standard hydraulic gear pump.


Gear pumps leak oil between the gears, while a piston (such as used in car engines) does not.  This means the piston pump will place the cylinder ram exactly where it is required, positioning the rudder accurately.  This gives far sharper steering, reducingunnecessary course corrections meaning battery consumption on Octopus pumps is up to half that of other pumps.


Leading autopilot manufacturers choose Octopus pumps for their non RFB pilot systems which do not have a Rudder Feedback unit. Previously, slop in the system caused by gear leakage meant that a Rudder Feedback unit was necessary to tell the pilot the exact rudder position. As Octopus pumps will always bring the ram back to the required position the Rudder Feedback unit is not required, which also greatly simplifies installation.


A professional installation should always have a method of isolating the pump from the steering system - Octopus pumps feature inbuilt shut off valves in the pump manifold.


A pump that does not have variable flow (unless dedicated to a range of cylinders such as our fixed 0.8L pump) will be operating too fast or too slow in 90% of cases.  Autopilot manufacturers get around this problem by adjusting the output to the pump to compensate, which either forces the pump to operate for longer periods of time which increases power consumption and wear on the parts, or it will operate at high pressure for short periods of time - also putting unnecessary strain and wear on the system.

Octopus Variable Flow Reversing Pumps precisely control the speed of the ram, reducing unnecessary battery consumption, pressure, strain and wear on the hydraulic system.

Getting the best steering performance for the boat

The flow rate of the pump can be set to get the best hard over time (cylinder ram speed) for the particular boat. 
There is a simple equation to calculate the hard over time:

                                                            FLOW RATE


A boat has a 200cc steering cylinder (ram) and a 12 volt system.  So either the OCTAF1012 or the OCTAF1212 would be suitable (see table below left).  
For this example we are using the OCTAF1212 which has a minimum flow rate of 600cc/min and a maximum flow rate of 1200cc/min:

MIN HARDOVER TIME: 200 x 60 = 20 sec

                                                                                                                    MAX HARDOVER TIME: 200 x 60 = 10 sec

The flow rate on the pump can be adjusted so that the hard over time is between 10 & 20 seconds - select which is most suitable for the particular boat.

The descriptions and guidelines shown on this page should be used as a general reference only. For any further technical information please contact our Technical Service. Contents of this website are based on the latest information available at the time of publication. CMP / Octopus assume no responsibility for the accuracy of the information contained herein. Product specifications are subject to change without notice.