[CA] [CA11] Autopilot Hydraulic Drive Bleeding

[stgermain45]

Hello,

I recently sent my Autopilot Type2 hydraulic linear drive (M81200) into Raymarine for repair due to hydraulic leaking. That issue is fortunately resolved after Raymarine's full rebuild. On installation and trial, the wheel would immediately turn when engaged (even past the stops if you let it). Again, fortunately resolved by a 1 minute call to Raymarine and getting the advise that I would need to reverse power +/- wires to the unit from the original installation. Odd, never would have guessed that! And great tech support!

However, now my problem is that the unit will NOT disengage when hitting standby after a bit of time in auto. In testing, I can disengage if reverting back to standby soon after engaging auto. This would indicate it's not an electrical issue (and I didn't change anything other than sending the drive in). However, if the unit is left engaged in auto for a longer period of time, the only way I can get back the wheel is to physically disconnect the + or - power cable to the drive motor (flipping the breaker to the electronics/autopilot does not do it). Sometimes the wheel will be freed after a prolonged period of time without having to disconnect cables. Raymarine phone tech support advised it was likely an issue with air in the system and needed bleeding. However, I didn't fully grasp the bleeding procedure. Can you please outline the steps on how to resolve this issue?

In case it's useful in some way:
ST7000+ Control Head (nav)
ST6000+ Control Head (helm)
T2 Linear-Hyd Drive (M81200)
T300 Course Computer
Fluxgate Compass
Rudder Indicator

Thanks,
Chris

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum Chris,

Mechanical linear drives, hydraulic linear drives, and tiller drives (those which are driven by a separate autopilot course computer or ACU) feature a clutch which is responsible for engaging and disengaging the drive unit. Accordingly, the drive unit's clutch leads must be connected to the autopilot course computer or ACU. When placed into Auto or Track mode, 12V is applied to the clutch leads by the course computer or ACU. When place in Standby mode, this voltage should drop to zero. Should a multimeter be connected to the clutch terminals of the autopilot course computer or ACU and these voltages be observed, then it would appear that there is a fault within the drive unit, necessitating that it be returned to Raymarine’s Product Repair Center to be bench checked / serviced. Should these voltages not be observed, then it would indicate that that autopilot course computer or ACU has suffered a failure and should be sent to Raymarine’s Product Repair Center to be bench checked / serviced. (applies to SPX or later autopilot course computers and Evolution ACUs).