I recently hauled out and decided to drain the gear oil from the Bowthruster, the oil was good and not cloudy but after two years needed changing.
Then after replacing the oil drain screw filled up the oil reservoir with 90 weight gear oil. The problem is that the gear oil will not flow. There is obviously some kind of air lock. I managed to get about 250ml in by Blowing into the reservoir, i.e. pressurising it.
I have now left the boat for the winter and maybe the oil will work its way down by gravity.
I looked for a bleed screw to let the air out but found nothing.
Does anyone know if there is a air vent bleed screw? Or is there some trick?
AML 54-019 ashore at the Bazimakoplou boat yard Kilada Greece