Auto. Pilot Hydraulic Pump

[Bay Retriever]

Mainship Auto Pilot Hydraulic Q
I have owned my 2004 Mainship for 5 years now. Have bled the hydraulic line at the upper helm myself and also replaced the steering ram two years ago in an effort to rid the boat of intermittent episodes whereby the autopilot looses control and the boat goes into an uncontrolled 360. (mostly in following seas).
Recently, a local marine tech familiar with Mainships, indicated that the cause of the problem could be a faulty hydraulic pump that resides behind the upper helm dashboard. Apparently, the pump pins, which open and close the hydraulic line in response to the Raymarine digital control head, could be one of issues. The theory is that this might also be the source of where air is slowly getting into the hydraulic line…. thus the need to bleed the lines every year or so.
OK Mainship Brain Trust…what do we know??

 

[sunchaser]

Just a thought - The rudder position indicator and AP may be mis communicating. Wiring, ground faults or voltage spikes may be at play. What brand of AP do you have?

Another thing to check is carbon buildup in the pump from brush wear. SOP is to remove the cover/rings from the pump and vacuumed it out.