Originally Posted by pcmm
Usually the autopilot pump drives the same ram as the regular steering so you just drain the main system and refill. How does the AP overcome the resistance of the main steering ram? If the AP has its own resvoir just drain it and refill it.
I have quadrant steering with cables
so no other ram. The autopilot is essentially self contained. Has its own separate steering quadrant arm mounted to rudder
The autopilot pump looks like this and the reservoir is on top which is the tank. No obvious drain plugs from the outside. I will look closer and see if there are any bleed screws.
I've bled plenty of motorcycle brakes in my day and for that it's a gravity system with the bleed nipple on the disc caliper.
Just sucking the fluid or draining from the tiny tank won't replace the volume of fluid in the ram. Need to get that fluid either drained or pumped out somehow.
Originally Posted by GordMay
“5.1 Oil filling and bleeding
When installing a pump unit, it is recommended that the whole system be emptied and refilled. Use a well known oil of a viscosity meeting the specification of the steering gear
Start by opening all stop cocks in the pipes leading to the pump unit. Simultaneously fill the steering wheel pump with oil whilst turning the wheel itself, back and forth.
Proceed by opening the couplings at the rudder cylinder whilst still turning the wheel, this will assist in creating pressure within the system, continue until clean oil is seen at the couplings. Now tighten the couplings. Then open the 3 couplings on outlet A, B and C on top of the pump unit, and repeat the same procedure.”
5.1 (Page 25) ➥ https://www.simrad-yachting.com/Root..._manual_EN.pdf
Thanks Gord I saw that manual and have it printed out. From the sounds of it they are assuming you are using hydraulic steering
and would fill it from the reservoir on the steering wheel, which makes sense from other diagrams. I have cable steering so the only options have to be on either the pump or the hydraulic ram.
It's a fairly simple system and my pump is the high point in the system. My thoughts were to crack open the hydraulic lines leading to the pump in lieu of a bleed nipple. Cycle the ram back and forth to push all fluid out the lines into a catch can. Use a syringe with a hose to suck the fluid out of the pump reservoir if it doesn't automatically drain when I remove the hoses.
Assemble the hoses again, fill the reservoir with new hydraulic fluid and cycle the pump back and forth. Since the pump is the high point, the displaced air will get bled out the reservoir tank. The tank isn't very big and I'm thinking there is far more volume of fluid in the cylinder. Which makes me think of geyers of hydraulic fluid going everywhere and it's a confined space.