Power steering fluid--what kind?

* Older Hynautic System (1983). Does one have to use the Hynautic fluid or are there other acceptable substitutes? Thanks

A good ISO-15 hydraulic oil or 5606 aircraft hyd oil - the red stuff that looks like strawberry juice - but don't drink it and never ever use Skydrol. You can also use Univis which is a clone of 5606.

Rick, didn't some of the older Hynautic systems use antifreeze?

Do any of the local auto parts stores carry any of these? Do I need to go to an airport maintenance facility to find these? Trying to avoid the very expensive Hynautic oil at WM. Thanks

Jay N wrote:
Rick, didn't some of the older Hynautic systems use antifreeze?

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*MY old boat had it when I bought it....converted to regular hydraulic fluid/seastar steering fluid


-- Edited by psneeld on Saturday 7th of January 2012 07:16:40 AM

Fighterpilot wrote:
* Older Hynautic System (1983). Does one have to use the Hynautic fluid or are there other acceptable substitutes? Thanks

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*On my last boat I just used Sea Star steering fluid...that's what the PO used on my new to me 1988 trawler.* Almost any fluid would work for this type of application...just the seals I would worry about.

*

If the fluid is red...the standard cheapo replacement for many boaters is regular power steering/tranny fluid either generic or Dextron.

If clear...any decent quality hydraulic oil of not too high viscosity should work onless you boat in extreme temps.

I know my answers aren't techie or yachtie...but having worked on poor little company commercial boats for the last 10 years...sometimes no matter what others seem to think is the only or right answer...lots of other things work just fine.* As long as someone didn't use bad or improvised seals

*


-- Edited by psneeld on Saturday 7th of January 2012 07:29:43 AM

I have a Hynautic manual. Doesn't say what year but the pump, etc looks like what I have. It says you can use the fluid Rick B said or Dextron type tranny fluid.

If you want that manual send me an e mail

leonaj99 at yahoo dot com

Looking for something red, since I am having a hard time finding a leak. Present fluid is clear. Need the proper viscosity since our temps. range fromt he 20's F to 90 and 100s F. Before I use tx fluid would like to find mil H 5606 equivalent in red. Thanks for the advice.

Fighterpilot wrote:
Looking for something red, since I am having a hard time finding a leak. Present fluid is clear.

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You can always use a UV tracer dye in the clear stuff. Even with red fluid, it takes a pretty good leak to be visible unless it drips on something light or puddles.

I use the tracer dye for fuel, hydraulic, and water leaks. It works very well and all you need is a small LED UV flashlight to poke around until the leak flashes into view.

Good idea Rick. Hynautics at WM is $25.00 a quart. Hate to put that in knowing I have a leak. None of the auto parts stores carry anything that meets mil L 5606. Check with local airport operator and he didn't have any but could order it. Guess I will have to get it on line or have him order it, assuming that would be cheaper than the $25.00 a quart stuff. Thanks

Jay N wrote:
Rick, didn't some of the older Hynautic systems use antifreeze?

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*Hynautic used/uses antifreeze in their hydraulic engine control systems (throttle and gear) - their power steering systems uses hydraulic oil.

Problem solved. Local airport gave me a link to their supplier of aviation hydraulic oil. Aircraft Spruce. Found their Phillips 66 X/C 5606H and 5606A Aviation Hydraulic Fluid selling for $6.50 a quart vice WM $25.00 a quart Hynautics. Bought 4 quarts with shipping included for $31 and change from Aircraft Spruce. I like to support my local businesses but $25.00 versus $6.50 is a little bit to much to pay for supporting your local businesses, expecially since I wanted 4 quarts. No tax and shipping but $6.00 Thanks for your help.


-- Edited by Fighterpilot on Saturday 7th of January 2012 06:30:30 PM

I know this is an old thread, but I was searching for hydralic fluid for my old Hynautic steering system, this thread came up. Thanks for the lead to Aircraft Spruce as I just ordered 6 qts of phillips 66 X/C.

You can use Seastar hydraulic steering fluid as well. Most marine stores stock it.

Like you said at $30 a QT at WM or $30 (shipping included) for a gallon of phillips 66X/C.......

I was just mentioning it as it easier to find without having to order it. Sometimes you need it now, not in a few days.

And I don't know why you would pay $30 a quart for it when you can find it for under $18 a quart.

Alaskan Sea-Duction said:

I know this is an old thread, but I was searching for hydralic fluid for my old Hynautic steering system, this thread came up. Thanks for the lead to Aircraft Spruce as I just ordered 6 qts of phillips 66 X/C.

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Me too! I have the original gallon from when the boat was sold on board and it's about gone. Thank you all for awakening the thread again, very timely.