I have two helm stations on my 26. Lately the upper helm seems terribly stiff. It used to be pretty loose. And it seems as if now there are fewer turns lock to lock, though the range of motion of the outdrive tillers is still 100%.
The lower helm seems the same as ever, which is to say firm but not stiff. I can see no signs of fluid leaking anywhere. The reservoir sight glass shows it to be about 5/8 full, as it has been for as long as I have owned the boat.
Since the lower helm has not changed I do not think that there is a problem with the ram or the linkages to the outdrives, everything thereabouts seems to move fully in range and show no signs of binding or leaking. So I am guessing that whatever changed is in the upper helm itself.
I did pump a little air into the reservoir prior to launching last week to bring the pressure up some.
Any ideas? Where should I start looking? How should I go about trouble shooting?
I don’t mind doing fussy detailed work on hydraulics if repairs are warranted, but I am strongly inclined that if an older hydraulic system is working and not leaking I am not going to start taking it apart without a definite plan of attack.
Peter
Hydraulic Helm Question
Moderators: CaptPatrick, mike ohlstein, Bruce
OK... I have to correct one thing: I only owned this boat for about a month before it went to the yard and was repowered. The hydraulics must have been taken apart during that process, so when I say that things haven't changed it can only mean that they haven't changed since the repower. But that was several years ago.
I have done some poking about trying to get information on the Hynautics systems. One thing that has come to light is that if there is air in the system then the wheel does indeed make more turns lock to lock.
And if that is the case it makes sense that the wheel would be easier to turn because you are moving less fluid per turn, and yet it still takes the same amount of fluid to move the cylinder to its full extention. So in essence it "feels" like a different gearing.... lots more turns to do the same work.
So it seems that my adding a bit more air pressure to the system pushed a little bit more fluid up to the top helm filling it properly (compressing any air bubble there?) and thereby reducing the number of turns but at the expense of making it feel stiffer.... So far OK by me... there are tables that tell me how many turns the wheel should go from lock-to-lock for various helm/cylinder combinations.... but my cylinder isn't listed among them.
However the number of turns range from 4.4 to 10. the 10 is with a pair of big cylinders. I have one fairly small one. So I figure I should be closer to the lower count. Right now I get 5 turns, which is a lot less then my previous 12+. This is a good thing. 12 turns lock to lock is a helluva lot of spinning to maneuver near docks and such!
Anyhow, the implication seems to be that the upper helm was never bled completely to begin with. Probably some small bubbles coalesced up into the helm over time after the initial bleeding. So I am thinkning I should do a proper purge and bleed on the whole system....
Am I on the right track? Or am I missing something?
Peter
I have done some poking about trying to get information on the Hynautics systems. One thing that has come to light is that if there is air in the system then the wheel does indeed make more turns lock to lock.
And if that is the case it makes sense that the wheel would be easier to turn because you are moving less fluid per turn, and yet it still takes the same amount of fluid to move the cylinder to its full extention. So in essence it "feels" like a different gearing.... lots more turns to do the same work.
So it seems that my adding a bit more air pressure to the system pushed a little bit more fluid up to the top helm filling it properly (compressing any air bubble there?) and thereby reducing the number of turns but at the expense of making it feel stiffer.... So far OK by me... there are tables that tell me how many turns the wheel should go from lock-to-lock for various helm/cylinder combinations.... but my cylinder isn't listed among them.
However the number of turns range from 4.4 to 10. the 10 is with a pair of big cylinders. I have one fairly small one. So I figure I should be closer to the lower count. Right now I get 5 turns, which is a lot less then my previous 12+. This is a good thing. 12 turns lock to lock is a helluva lot of spinning to maneuver near docks and such!
Anyhow, the implication seems to be that the upper helm was never bled completely to begin with. Probably some small bubbles coalesced up into the helm over time after the initial bleeding. So I am thinkning I should do a proper purge and bleed on the whole system....
Am I on the right track? Or am I missing something?
Peter
Last edited by Peter on Jun 26th, '11, 12:45, edited 1 time in total.
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In Memory Walter K
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If you have a Hydnautic system, look and/or feel under the reservoir unit to see if you have two approximately 1/2" nuts mounted one over the other or side by side under it. Those are the "bleeders". The rest is a two man job. One person turns the wheel while the the other "cracks" one bleeder nut only a few turns. As the wheel is turned air will bubble out from under the bleeder nut until a steady stream of fluid starts emerging. Then lock it down. Repeat with the other nut. Hopefully, someone will chime in with a more complete procedure as this is what I learned when I lost steering on my bridge but still had it down below. A real professional bleeding also includes doing the autopilot line, too if you have one. If it doesn't have the bleeder nuts, I was told you could do the same thing by cracking the two (I assume one at a time) hose fittings going in and out of your piston ram that pushes your rudders.
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