hydraulic steering fluid leak

[REO]

My 1984 27 sport boat has hydraulic steering with a nicely installed autopilot, installed by previous owner. The unit directly behind the steering wheel is leaking. I suspect that the system was serviced when the new autopilot was installed, but am not sure. There is a short hose leading to a filler with a screw cap on the dash. There is enough leakage to leave a coating on the wire below the unit, but I can not see drips when the wheel is turned. I have never worked on hydraulic steering. What can I do to diagnose the problem, and what are the likely issues?

[Norseman]

Which steering hub/pump do you have?
Pictures would help.
I had wires behind the panel coated as well, Sea Star “Traditional Tilt Helm” by Teleflex: The small leak came from me filling the reservoir using a small funnel instead of the factory adapter, the fluid migrated under the cover and into the compartment behind the instrument panel.
Did not find the mess for a couple a weeks.
Cleaned it up and scratched my head: No leaks, the only possible cause was the funnel bottomed out without sealing the filler opening.

[REO]

I did some research and I sure didn't know what I didn't know. I added power steering fluid a few years back because it looked low. Looks like I contaminated the fluid and may have done some damage to seals and probably over filled. I'm going to clean up the area and see if I can drain the system and fill with the proper fluid and a filling and bleed kit. Steering worked fine, so I hope this will solve an overfill leak??
Any suggestions on bleed kits, and what I should be doing are appreciated. I'll look at what system I have and post that info.

[Norseman]

Bleed at the steering cylinder, the only kit would be the factory filler adapter and a bottle of fluid if you have the SeaStar
(I am fairly current on that procedure as I replaced the steering cylinder 3 times this year)

[REO]

20210820_121110.jpg

The steering head is Sea Star
model 1.7 helm RM
Part # HH5261

I was able to slide the whole unit with hoses up where I can see it. All fittings are covered with a goop that I think is a combination of hydraulic fluid and fiberglass sanding dust. After cleaning everything I spun the wheel several times looking for a leak. Nothing. The wires under the unit are coated in a fine film of fluid. The head is nearly full and the fluid looks clear. What fluid should I use? When I turned the wheel the filler hose was detached. Did that keep the pressure low enough that it didn't leak?

[Norseman]

. When I turned the wheel the filler hose was detached. Did that keep the pressure low enough that it didn't leak?

Filler hose?
Hmm, not sure what you mean? The adapter with a plastic hose that screws into the filler hole?
The pressure has nothing to do with the hose being on or off, or the cap being on or off.
The pressure is between the pump and the cylinder, no pressure in the reservoir that I am aware off, although it has a vent in the cap, or some of them do.

The fluid level should be almost to the cap, if too low you get air in the system.
Too much and it may make a mess.
Do a good bleeding and use the Sea Star fluid, I tried other and cheaper fluids, one of them was a pure mineral oil as recommended by the place that overhauled the cylinder but it made the wheel harder to turn.
The factory fluid can be $26 a quart but look at a discount place like Walmart for cheaper bottles. If the fluid is old, replace all of it and by a gallon container.
Look for leaks at the steering cylinder and leave an oil soaking engine diaper under the cylinder at all times so know it is starts leaking or not.

[REO]

Can I bleed the system by just turning the wheel and filling the reservoir as it draws down, or do I have to bleed off air at the ram like bleading brakes on a car?
I hope I just over filled. It doesn't seem to take much of the hydraulic fluid to make a big mess.

[REO]

I found a good utube on bleeding the system. I will use the system that runs plastic tubing from both ends of the ram up to a fill container. I can now see that my system has mineral oil in it. I'm off to buy some tubing and mineral oil this morning. It's predicted to be about 95 degrees here today, and The boat is in a metal pole building. Work in the shop ends about noon. So, this may not get done today.

[Norseman]

You probably need 2 guys to bleed the cylinder: One to turn the wheel, the other guy to open and close the valves on the cylinder.

[SalishAire]

Have you looked into a rebuild kit for the helm. Its been a number of years but my recollection is that it was not a hard process and the kits are available.

[REO]

We finished the bleed process. I made the bleed kit and attached the tubes securely with hose clamps. Once the tubes were securely attached and oil was poured into the funnel at the steering wheel I left the bleed screws on the ram open while turning the wheel left and right. I removed the steering head unit and braced it against the dash so I could easily check for leaks while turning the wheel. I guess I could have rebuilt the unit since it was already out, but I suspect it was rebuilt by PO when the dash was rebuilt. I could detect no leaks.
I should have paid more attention to your earlier post, and only got a quart of mineral oil. We live on a mountain lake 25 minutes from the little town. Took two trips to get a gallon of mineral oil. It took a lot of wheel turning to flush out the old oil, but there was a lot of air in the lines. I don't know what caused the coating of oil below the unit. Maybe an overfill? I got everything cleaned up and reassembled. Steering is much better. I'm going to take your advice and put a cloth below the head to monitor for future leaks. Thanks for the help

[Norseman]

. but there was a lot of air in the lines.

If you left the bleed screws open while turning the wheel left and right you probably sucked air in: Just like bleeding the brakes on a car, push the pedal in and have somebody open the bleed screw, then close it before taking your foot of the pedal.
Try to bleed the steering again closing the bleed nut after you turned the wheel one way and before you turn it the other way.
Rinse and repeat.

[REO]

The system I used created a closed loop for the fluid to exit the ram and go to an external vessel that feeds the steering head. Clear tubing from both ends of the ram fed the main tube to the filling vessel. There is a very good utube on this system. Having both ends of the ram open didn't cause a problem. I could see the fluid (and air bubbles moving through the tubes. After the tubes were running clear of air bubbles I ran the system for several minutes to be sure all air was purged. then I closed both ends of the ram and pinched off the feed tube to the head and removed all tubing. The system worked well. You are correct it was easier with two people.

[Norseman]

. There is a very good utube on this system.

Please share the link.
Thx

[REO]

I can't get the link to work, but if you search youtube under "How To Bleed Marine Hydraulic Steering EASILY" it will come up. I used the system to change fluid by putting the return line in a separate container until the old fluid was out, then put the return line back in the circulating container and circulate until no bubbles appear. I think there is a kit for sale to do this, but the clear tube and t fitting worked fine for about $25.