Steering hydraulics, play

[Phrancus]

Our 1992 26/28 fly has below and top steering. One engine has a hydraulic steering pump with a reservoir. USA text on it so I suppose it is original (?).

The steering is not much fun, lots of play (have to turn with nothing happening in between from left to right) so I suppose (from comments elsewhere) that there may be not enough oil in the system.

Here's a picture of the steering column up top. You see the dials have been replaced at some time in the past, they don't show much realistic values (RPM, temp) but do show relative values (I mean: they move and at high temp the temp indeed shows high. But the RPM values are off. I see no adjustment possibility so I suppose they chose the wrong type for the Volvo tacho pulses)

56131.jpg

is there a filling possibility there? Is there another procedure to this issue?

Do I fill it with the same oil that is in the reservoir at the engine? Sounds logical to me but I expected that reservoir to also keep the system from developing an air bubble up top so I might better ask first and tinker later.

Drives have no play, piston behind the engine and the rods are all tight (enough) so I ruled those out as causes.

[Cooler]

There should be a container reservoir in your engine compartment. That is why you have 3 lines coming out of the helm pump. That looks like a Hynautic system. It is obsolete, but the helm can be rebuilt if the seals start to leak. I am surprised your seals are not already compromised being that low on fluid. I replaced my Hynautic with a SeaStar helm that I can fill at the helm pump location. You are very low on fluid. You need to use Hydraulic Steering Fluid to fill. Make sure it is Hydraulic Steering fluid and not power trim/power steering fluid. Some providers label their fluids in a confusing way. Seastar and Quicksilver have their containers accurately marked. If you can simply fill that reservoir up, make sure you bleed the system to get all the air out of the lines. A good mechanic will have a bleed system that hooks up to the helm and the steering arm. It gets the air out in 15 min when used. Otherwise, you need help from another person to turn the helm while the bleed valve is held open. Doing that bleed process manually can take an hour or more. Make sure you get this done soon. Sounds like you are very close to losing your steering completely. Good luck! er

[Phrancus]

Thanks for that information.

I found a video on how to replace the O-rings on the steering 'hub'. The one on top is dry, the one inside is a bit sweaty. Both used very little but old. I'll see how to get the O-ring set, probably have to get it from the US.

There was supposed to be a link to information on how to bleed that system but that link didn't work so that's next to find out. Also handy to know where the bleed valve is located, for the manual procedure or to pressurize the system.
EDIT: well that was quick: link I guess I got the reservoir wrong as per the picture below. The one I thought to be for the tilt looks like the one in the manual.
Here is more on the workings of the bleeding link
looks like I just need to do the helm-bleed part for now.

Now I need to figure out what type this is so I can get the seal kit via eBay.

As for the fluid, I have two oil reservoirs:

I thought this one is for the whole steering system, enough fluid in there but that apparently has a different function, don't know what. Never thought about it or looked at where the hoses go. The stern tilting has their own pumps, the trimflaps had (removed at some point in time) their own pump so what this one is doing there I don't know.

Screenshot_2022-04-21-19-14-45-034_com.miui.gallery.jpg

And here is the steering reservoir with bleed valves at the bottom and the pressure plug on top.

IMG_20201029_094828.jpg

So I should be able to bleed the system to see if that helps and at the same time get two of those gasket sets to overhaul the hubs.

[bud37]

Check out some hydraulic repair shops near you......the "o" rings can be just generic and they may have them in stock with the sizes you need.....good luck with your repair...

[km1125]

I got this from a friend a while ago when he rebuilt his hynautics. He bought the parts locally...

Hynautic_parts_orings.jpg

[Phrancus]

Thanks, perhaps they lead to some dimensions so I can get my local parts store to work (I'm in Europe). Taking it apart and then having to source the parts may be a bit of a problem timewise. But first things first: I don't mind filling it a couple of times untill there is time to get that done.
I'm not that afraid of loosing steering, what we do here I could do on throttle with a bit of practice as well.


EDIT: I found a thread where that image/list is mentioned as well. I post the procedures and drawings here for future use for anyone stumbling over this thread.
Four PDF files (forum does not allow those uploaded directly so here's a zip file)
- 3 line purge (for pumps / helms that do NOT have a bleed screw, if you have 2 then find the 2 line purge file (**1)
- H50 shows an exploded view of the pump (helm) so you have a chance to put it back together as it was should you forget to line things up nicely on your clean workbench)
- rv 55 shows an exploded view of the reservoir/pressure holder unit
- Zatkoff is the list as posted above

Hynauticdocuments.zip

Should I get to the point of taking the pumps apart, I will post dimensions here to aid in finding replacements.

[km1125]

EDIT: I found a thread where that image/list is mentioned as well. I post the procedures and drawings here for future use for anyone stumbling over this thread.

That guy (Matt) is a member here as well but he hasn't been active in a while. He's got a lot of projects listed in the "projects" forum and probably posted similar info on the Hynautics somewhere here.