Sea star hydraulic system gremlin

[Derek]

Noticed sloppy steering and was checking fluid and noticed it was completely full of red ATF which apparently is a big no-no with sea star product. Was underway so no choice but to top off with sea star. Went below and noticed fluid on ramjet seals so those were replaced. Started leaking an ounce or so per trip from upper helm so new helm seal kit installed. Still leaking and not from the bottom or hose connections. Ordered new vented air cap…. Still leaking. Pulled into river to Brunswick and heard a weird buzzing and as I opened the cap to check fluid shot out with some force behind it. No steering g at this point and autopilot lost rudder indicator status. Topped off fluid and spun wheel to burp it and was able to get to marina.

Went up there and really cleaned up, added more juice and now it seems to be happy. I know I need to bleed out the old ATF, but my buddy says the reservoir at the helm should not be pressurized. Ideas?

 

[Gdavid]

Your buddy is right, the upper helm cap should have a vent on a sea star system. There are two versions of the cap and only the highest in the system should be vented. You can just drill a small hole (1/16") in it, clean and reinstall.

 

[twistedtree]

I can't quite tell which helm you are talking about at various points, so just to confirm....


The vent cap, filling, and checking fluid are all only on the upper help, right? The lower helm doesn't have a vent and you aren't opening any plugs there, correct?


I'm not aware of the Seastar ATF prohibition, but expect it's an incompatibility with their seals. Your leaks would suggest the same. It should have been removed in conjunction with resealing the help pump and ram, or it might just trash the new set of seals.


It sounds like you just still have a lot of air in the system. Or at least that's what I'd work on first, while at the same time monitoring for leaks. It can be deceptively difficult to get the air of steering systems depending on how the hose/pipe runs work their way through the boat, especially where there are any high spots that can hang onto air bubbles.

 

[Derek]

Your buddy is right, the upper helm cap should have a vent on a sea star system. There are two versions of the cap and only the highest in the system should be vented. You can just drill a small hole (1/16") in it, clean and reinstall.

Sorry for the confusion. The new cap is the vented one which I am guessing explained the hissing/vibration. FWIW, I was blowing out the engine at near WOT so there was more stress on the rudders than usual.

 

[Derek]

I can't quite tell which helm you are talking about at various points, so just to confirm....


The vent cap, filling, and checking fluid are all only on the upper help, right? The lower helm doesn't have a vent and you aren't opening any plugs there, correct?


I'm not aware of the Seastar ATF prohibition, but expect it's an incompatibility with their seals. Your leaks would suggest the same. It should have been removed in conjunction with resealing the help pump and ram, or it might just trash the new set of seals.


It sounds like you just still have a lot of air in the system. Or at least that's what I'd work on first, while at the same time monitoring for leaks. It can be deceptively difficult to get the air of steering systems depending on how the hose/pipe runs work their way through the boat, especially where there are any high spots that can hang onto air bubbles.

Thanks for he questions. The lower helm does have a cap but it is the solid non vented cap. On the bleeding, the guy that did I the seals didn’t really spend any time bleeding other than me spinning the wheel a few times so it could have a big bubble between stations and ram.

 

[Derek]

Copying this for any other sea star users. http://www.seastarsolutions.com/wp-...01/Hydraulic-fluid-Product_Specifications.pdf

 

[Portage_Bay]

Some comments on fluid for hydraulic steering systems. I don't think you need to use SeaStar's expensive fluid. Of course you can't go wrong with SeaStar fluid. But there are alternatives at 1/2 to 1/4 of the price. OP has some steering issues that may require possible flushing, certainly bleeding and perhaps some repairs. He may go through quite a bit of fluid. When in his shoes 2 yrs ago I went through 1.75 gallons of fluid.

Reading the PDF in post #6 I think there are some important points. SeaStar says recent changes require the use of their fluids. How recent? What changes? In a newer system I might take the bait and use their fluid. But how new is that? OP's boat is 2005.

According to SeaStar one of the acceptable fluids "In an emergency" is MIL 5606. A bit of research will turn up it is the same viscosity as SeaStar's. Also 5606 is an air craft mineral oil hydraulic fluid. For use in aircraft it has to be very clean, contain no moisture and be able to perform in a much more demanding environment that our boats operate in. Numerous posts here on TF and elsewhere discuss the use of 5606. Variously named MIL-SPEC or MIL-PRF and sometimes with an 'H' on the end. If it's 5606 it's all the same stuff.

Is SeaStar telling the whole truth? Or are they promoting a high profit item to their benefit?

SeaStar notes that emergency alternative fluids need to be filtered through a fine mesh screen. I have to think that air craft fluid is already clean enough.

You can find 5606 in non-resealable containers and resealable containers. The non-resealable is much more expensive. I have it from an aviation service shop it's the same stuff. The difference is with a resealable container it's up to you to keep it clean.

Note that 5606 is red. The fluid in OP's system may be ATF or it may be 5606. Without knowing what's in there it might be best to drain and flush with the fluid of choice.

The boat's steering system is critical equipment. Occasional flushing is a good idea. When I did mine the fluid had been in there who knows how long, I had only owned the boat a year at that time, and drained a brown color. I've seen other boats with fluid in the same condition. If it isn't clear as water or the red of 5606 it's past time for a flush.

The biggest single advantage I can see to using SeaStar fluid is that it is readily available nearly any place that supports recreational boats. 5606 not so much. As with everything there is a work around for this According to Tony Athens at Seaboard Marine writing about steering fluids

Lighter viscosity fluids just about always make for easier steering.. ATF (Dextron) works well in some systems, but if thinned down to about ISO 15 (using very clean #2 diesel — about 3 parts ATF and 1 part #2) you have a very inexpensive, proven steering fluid that will never give you issues when using the system designed around light oils (Hynautic, Wagner, Seastar, and some others).

 

[Stabi]

Some comments on fluid for hydraulic steering systems. I don't think you need to use SeaStar's expensive fluid. Of course you can't go wrong with SeaStar fluid. But there are alternatives at 1/2 to 1/4 of the price. OP has some steering issues that may require possible flushing, certainly bleeding and perhaps some repairs. He may go through quite a bit of fluid. When in his shoes 2 yrs ago I went through 1.75 gallons of fluid.

Reading the PDF in post #6 I think there are some important points. SeaStar says recent changes require the use of their fluids. How recent? What changes? In a newer system I might take the bait and use their fluid. But how new is that? OP's boat is 2005.

According to SeaStar one of the acceptable fluids "In an emergency" is MIL 5606. A bit of research will turn up it is the same viscosity as SeaStar's. Also 5606 is an air craft mineral oil hydraulic fluid. For use in aircraft it has to be very clean, contain no moisture and be able to perform in a much more demanding environment that our boats operate in. Numerous posts here on TF and elsewhere discuss the use of 5606. Variously named MIL-SPEC or MIL-PRF and sometimes with an 'H' on the end. If it's 5606 it's all the same stuff.

Is SeaStar telling the whole truth? Or are they promoting a high profit item to their benefit?

SeaStar notes that emergency alternative fluids need to be filtered through a fine mesh screen. I have to think that air craft fluid is already clean enough.

You can find 5606 in non-resealable containers and resealable containers. The non-resealable is much more expensive. I have it from an aviation service shop it's the same stuff. The difference is with a resealable container it's up to you to keep it clean.

Note that 5606 is red. The fluid in OP's system may be ATF or it may be 5606. Without knowing what's in there it might be best to drain and flush with the fluid of choice.

The boat's steering system is critical equipment. Occasional flushing is a good idea. When I did mine the fluid had been in there who knows how long, I had only owned the boat a year at that time, and drained a brown color. I've seen other boats with fluid in the same condition. If it isn't clear as water or the red of 5606 it's past time for a flush.

The biggest single advantage I can see to using SeaStar fluid is that it is readily available nearly any place that supports recreational boats. 5606 not so much. As with everything there is a work around for this According to Tony Athens at Seaboard Marine writing about steering fluids

THIS