There is a good discussion on this at Hynautic bleeding
but I am going to start a new thread because my question is not quite on track for the other thread.
I have not used the boat in a few months, due to events beyond my control, so when I went down there a couple of days ago to take it out I had no steering. I know that my hydraulic system leaks some, but usually if I just keep the reservoir filled then it is OK. But there was almost no hydraulic fluid in the reservoir this time. So I put some in it and pumped up the pressure.
Still no steering, though. So I figure the lines have to be bled. The link that I gave above has fairly detailed instructions on doing that, but I am having a problem trying to figure out how far to open the nuts to purge the air. I tried loosening one until it stopped, but it came all the way out, and hydraulic fluid spurted out. So I put it back in.
The two purging screws are not really screws at all. I am sending along a couple of photos to show what the unit looks like. There is a large unit which screws into the rectangular box, and then a bolt on top of the large unit with a nut on it. ??? Loosening the nut does nothing so far as i can tell, so I loosened the lower unit. And that is when it came out and spurted hydraulic fluid on the floor.
So if someone could help me with an explanation of how far (if at all) to open those two i would be grateful.