Hydraulic steering problem

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Bigfish

Senior Member
Joined
Jan 25, 2013
Messages
297
Location
USA
Vessel Name
My Lady
Vessel Make
Formosa 42 Double Cabin
Hi folks,

Embarrassing that I need to ask here but my ability to focus on things seems to be seriously declining lately.

I'm living on my 42' Formosa Trawler and pulled off my mooring ball last week in a stiff wind to go get my water tanks filled and I realized I had no rudder control. Fortunately I have two engines. I'm suspecting that I have a hydraulic leak. When I purchased My Lady four years ago, I vaguely remember mention of a leak and I believe it's up on the flybridge behind the wheel. I've never had a steering problem until last week.

How do I check the fluid level? and is there any trick to getting things back to normal??

Thanks for your help!:facepalm:
 
Depends on your steering setup but if like mine (seastar I and II) the fluid reservoir is on the wheel support, there is a little plug, unscrew it and look inside it should be topped by your hydraulic fluid. In different setup you may have a fluid reservoir somewhere on the line, should be easy to find as it should be accessible and on your hydraulic line. And finally if you lost your control because of a fluid leak, there should be clear evidence of the leaked oil as you must have lost a lot.

L.
 
Seastar sells a kit consisting of a pint or so of hydraulic fluid and a tube to connect it to the fill port on the top of the helm pump. Hook it up and turn the helm back and forth a dozen times to fill the top of the pump.

Sometimes you have to bleed at the steering ram, but if the leak is only affecting the upper helm then you can fill it as above with no bleeding.

David
 
My steering has a tank which has an air valve and fill cap on it. Can't remember the brand, have to look at my log book. Anyway had to change the seals in the upper helm and bleed the system. To bleed you loosened two nut on the tank and turn the wheel 20/30 revolutions each way. Tighten the two nuts on the tank and your finished.
 
You need to check what type of system you have. On mine, there is a reservoir near the rudder. There are some clear sections so you can see the fluid level. There is also pressure gauge and a Schrader valve on the top. The idea on mine is to fill the reservoir and then pressurize the system with a hand-pump. I've never had to add fluid but I have pumped up the system twice in the year that I have owned the boat. Mine calls for between 25-30 psi but the steering still seems to work at 0 psi.
 
The first winter we had our trawler (5 years ago ) the air bled down on the system and we had no steering . We had plenty of fluid in the reservoir. I just pumped it up to 25 psi and haven't had any trouble since.
 
The pressurized system is made by Hynautic. The company was purchased by Sea Star some years ago and the system is still supported. There is a third system that is found on boats made by Wagner, not many of those around.

All the previous comments are correct. If a leak was mentioned, you should only have to fill her up, if Hynautic then pressurize. Of course someday you will need to address the leak.

If you have a 2 station boat with a Sea Star system ONLY fill it at the upper station. As a vented system the lower station has a non vented plug and if you pop the lower station all the fluid in the system uphill will drain out, not pretty.

:socool:

Sea Star Helm -- Hynautic Helm -- Hynautic Reservoir
 

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If you have a leak then try to find it. It might be a pump leaking, it might be a loose fitting, it might be the cylinder needs resealing, or it could be a hose or line in trouble.

Find and assess to know why the leak occurs.

I saw a guy some years ago [25] lose his steering completely because he ignored a leak.

It was a line worn through at a too sharp bend rubbing against something else. Eventually the line let go almost completely with a loss of steering in a BAD spot to lose it. Unfortunately none of us had anything of any use to him. Oil yes but it just leaked out again. We didn't know enough at the time to figure out what could be done and although even then I carried a lot of fittings I had what I needed which were all the wrong sizes.

But seals wear and breakdown from age and can let go completely and abruptly causing some troublesome problems.
 
http://assets.suredone.com/2622/med...ic-reservoir-capacity-2-quart-hp5810hy-md.jpg

I have that same Reservoir, But I can not read the bleeding instructions on it because it is worn. Does anyone have a clear image or copy paste those instructions?

I am hoping that my upper helm shaft seal replacement is all I have to do to fix the clunkyness on my 84 Californian 34 after I replace seal refill tank and put back to psi 20-30
 
Keysdisease nailed it in my opinion.

I only have one comment to add to his post, you look like you have two stations, if both lost steering, then you probably lost fluid below the lower helm pump. If it's not a pressurized system, that means you've lost a lot and you should start looking for the leaking fluid at the ram and work forward.

If the lower station works but not the upper, then you are low on fluid and the leak could be anywhere from the level of remaining fluid to the ram.
 
http://assets.suredone.com/2622/med...ic-reservoir-capacity-2-quart-hp5810hy-md.jpg

I have that same Reservoir, But I can not read the bleeding instructions on it because it is worn. Does anyone have a clear image or copy paste those instructions?

I am hoping that my upper helm shaft seal replacement is all I have to do to fix the clunkyness on my 84 Californian 34 after I replace seal refill tank and put back to psi 20-30
I'm working from memory here having overhauled my Hynautic system this winter. When I get near the instructions I'll correct if there are errors.

1 fill the reservoir 3/4 full. Pressure to 35 lbs.
2 bleed at the ram. Bleed valves if you have them. Crack the fittings if not. Bleed until you get no air.
3 open the port or starboard relief valve
4 turn the upper helm to port 40 slow revs. Hint, if you hit the stops you opened the wrong relief valve.
5 repeat at the lower station.
6 close the port relief valve, open starboard
7 40 slow revs upper then lower helm
8 close starboard relief.
9 check both helms lock to lock for proper operation
10 now run the autopilot pump, not before the helms function properly.
11 adjust fluid to 2/3 full. Pressure to 20 - 25 lbs
 
Thanks Ray, think Im about to hire someone (ugg) because my tank has no bleeder valves only two small plugs on the top of the steering pump. I bought a fill kit for filling the upper helm bit the plug is the wrong size to match up with the kits male plug adapter / hose.
 
The bleeder valves if present will be on the ram. If not you crack the fittings.

The reservoir has no bleeder valves.

You fill at the reservoir after relieving the pressure.

Don't open any fittings or the reservoir before relieving the pressure at the tank top with what looks like a tire valve. It get real messy real fast if you don't.

When I get home where the manual is I can copy the relevant pages and send to you.
 
SeaRow,

And others with Hynautic steering systems. Here's a PDF of the manual, it's easier to read than what I can do copying my old well used manual. It is a PDF I suggest you download and keep. I strongly recommend you follow the bleeding procedure to the letter. It makes the job much easier and it goes a lot faster.

http://boatsteer.com/assets/Hynautic_1987.pdf

My comments on Hynautic:

In my opinion it's a high quality system with a long service life and still supported by SeaStar. Keep in mind I am not a hydraulic steering systems design engineer. I've just been around them for more years than I care to admit. As I understand the design of the system the basic concept is no different than any other hydraulic system. Helm pump(s) and autopilot pump move the fluid one way or the other causing the ram to move and turn the rudders. Air in the system causes troubles, a little air makes the system soft and less than positive. A lot of air will cause failure. Air gets in from leaks or sloppy fill and bleed procedures.

Hynautic has added a pressurized reservoir that can be placed lower than the helm pump(s) and autopilot pump. I see some advantages to this.


  • Once you have most of the air out of the system it will be self purging for small amounts. Some hydraulic systems can take a lot of effort and a long time to work all of the air out leading to less than positive control.
  • The system is sealed from the atmosphere keeping moisture in the fluid to a minimum.
  • Larger boats with longer runs need an expansion tank to handle volume changes with temperature. Some boats use the upper helm for that purpose. Larger boats will need a reservoir open to the atmosphere above the uppermost helm.
  • A quick glance at the reservoir on your daily checks will show any change in pressure beyond normal changes due to temperature variations or level alerting you to leaks in the system.
My comments on the fluid to be used:

There has been discussion on other threads about the fluid to use. As always lots of opinions, some backed up by facts. I decided to go with MIL spec H-5606 oil rather than "boat hydraulic steering fluid". The former is available for $29 a gallon, the latter $29 a quart.

The manual calls for Hynautic's own fluid. Or a quality MIL spec H-5606 fluid. The reservoir label on my system simply says MIL spec H-5606 fluid. MIL spec H-5606 is a military specification for aircraft hydraulic oil. To lose control of an aircraft due to hydraulic fluid problems is fatal. It's got to be good enough for a boat's steering system.

If you decide to go the H-5606 route I found two versions available at the local aircraft service shop. Quarts that are non resealable for single use throw away any extra and selling for nearly as much as the boat fluid. Gallons that are resealable and sell for $29. According to the owner and lead tech of the shop there is no difference in the fluid, just the packaging and intended use. I bought the gallons and will keep the extra tightly sealed in a dry place. I'm confident it will be good enough for topping up should that be required.
 
I sent the pump to seatech in San Diego, hope to get it back soon and go fishing!

Thanks all.

Hopefully I can get the new pump in and the properly bleed the system.
 

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