I don't know if this thread covered the parts
of a hydraulic steering
system, but usually there is a hydraulic reservoir - a small round "tank" with a pressure gauge and "sight glass" tube somewhere in the system.
Maintenance wise you look at the "sight-glass" tube which shows the level of the hydraulic fluid in the reservoir and make sure it is about midway up the tube. Also there is normally a pressure gauge mounted on top or somewhere on the tank and it should show about 30psi or thereabouts of air pressure inside the reservoir tank. There is sometimes either a bicycle tire type air fitting on the tank or a small hand air pump hidden in the fill cap. This is how you "charge" up the air pressure in the reservoir tank. The purpose of the "air charge" is to keep the hydraulic fluid from "frothing" or having a "head" of bubbles that is inside the tank.
So long as you have fluid in the reservoir and the air pressure holds steady everything is fine and press on. If there was a leak the fluid would drain out and the air charge would bleed to zero. In which case you need to find the leak and fix it.
In a pure hydraulic steering
system there is normally a manual/hand operated pump attached to the steering wheel
. Turning the wheel
operates the pump which moves the rudder
ram and rudder
. Keeping everything clean and protected from anything getting wedged between the rudder ram and the rudder is common sense maintenance.
Other than that there is little or no maintenance necessary until something breaks or starts leaking. Carrying a spare quart or so of hydraulic steering oil
is a good idea in case a fitting starts to leak. You tighten the fitting and refill the reservoir.
connection to the hydraulic system is usually by a parallel electric
hydraulic pump the runs one way or the other as commanded by the autopilot
computer. But normally the hydraulic steering system is totally manual and needs no electricity when you are steering from the wheel. Each manufacturer normally publishes a recommended number of months or hours at which you should change out the hydraulic oil