Hydraulic autopilot - consumption

[Mako]

Does anyone have any idea of the volume of hydraulic oil per hour that your autopilot uses during normal operations? This number compared against the size of your steering cylinder would be useful information. Thanks.

 

[LarryM]

Not sure what you mean by 'uses' because the hydraulic fluid is pumped back and forth in the system and none is actually used. As for flow, there are so many variables, I don't know where to start. In calm water, the flow is almost nothing because the helm corrections are very slight. In a heavy following sea, the flow will be extreme.

I have attached the specifications for the Simrad range of reversible pumps that might help with your question. You will note that *** states "Typical average 40% of max. value." above Power Consumption. This might translate to the average Flow Rate as well, but I don't know if the pump output is linear or not.

 

[Greatlaker221]

Autopilots do not consume any fluid unless there is a leak. Each system will contain different volumes of fluid depending on the number of pumps, length of hoses,etc. Each model of AP, pump and cylinder hold specific but different quantities of oil. Go to Seastar.com they have good sizing information and cubic volume requirements. a AP needs to match the existing system to ensure it neither under steers or over streets. This is not a general question, it is specific to each application. Garmin has information about this on their website as well.