Identifying hydraulic fluid

[billbobthorpe]

I bought a new boat last year, 2001 Pro Line 25 walk. It has a Seastar steering system. I just added a Simrad autopilot and changed the seals on the Seastar steering ram. I need to bleed and fill the hydraulic fluid. I'm not sure what hydraulic fluid that is currently in the system. How can I identify the fluid? It is red in color but does not smell like ATF. I contacted the previous owner and they never touched the steering system so they didn't know what type of fluid that was used. Any help would be appreciated. 

[Andre wallyandre]

Seastar hydraulic oil: http://www.seastarsolutions.com/products/hydraulic-new/hydraulic-fluids/seastarbaystar-hydraulic-steering-fluid/

Edited February 28, 2022 by Andre wallyandre

[stinger]

You can use this fluid in your system at a fraction of the cost of the  Seastar fluid especially if you are going to flush the system.

https://www.amazon.com/Octopus-Hydraulic-Steering-Autopilot-Drives/dp/B07HBHVNPS

 

I bought a gallon of this last March for $35.29 delivered on Amazon and used it to flush my system with  Baystar steering and Raymarine Autopilot. 

Edited February 28, 2022 by stinger

[Tradman]

According to Seastar any fluid that meets mil spec 5606 is ok. I personally use Aero Shell 4 fluid, its red in color and costs about 1/2 of seastar fluid. Last gallon I bought was about $40 plus shipping

Edited February 28, 2022 by Tradman

[Tradman]

7 minutes ago, stinger said:

You can use this fluid in your system at a fraction of the cost of the  Seastar fluid. 

https://www.amazon.com/gp/product/B076136PZQ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

you did see that was  a quart price ?

[Tradman]

[billbobthorpe]

Thanks for your help everyone. I guess I'll flush the system and start with new and fresh fluid.


Sent from my SM-G991U using Lake Ontario United mobile app

[Andre wallyandre]

2 hours ago, Tradman said:

you did see that was  a quart price ?

Excellent price!

[Frogger]

Someone from Lou can’t remember, lead me to super tech hydraulic oil.  Spec H5606. 30.00 for 2 gallons.  Never looked back. 

[AnglingAddict]

I have heard of folks diluting ATF 10% with diesel fuel for use as a fluid used in marine applications.  I don't remember where I read that but I know I didn't make it up - seemed to be a pretty common practice on the forum that I read it on from what I recall....

[Andre wallyandre]

I would not use anything that is not meant for hydraulic steering specially if I intent to install a autopilot; a autopilot pump is not cheap.

[lost a lure]

Power steering fluid if your not concerned about it leaking into the water.

[mr 580]

I have a Simrad autopilot with Seastar steering and the install took less than a quart of fluid to bleed and fill.  IMO with the small amount of oil used there is little savings or reasons to use anything other than a manufacturer oil or a manufacturer accepted spec oil.  Not worth risking a pump or system failure.

[Sk8man]

1 hour ago, mr 580 said:

I have a Simrad autopilot with Seastar steering and the install took less than a quart of fluid to bleed and fill.  IMO with the small amount of oil used there is little savings or reasons to use anything other than a manufacturer oil or a manufacturer accepted spec oil.  Not worth risking a pump or system failure.

x2

[Frogger]

So I dug up the info from past research and recommendations.  Turned out to be a SeaStar tech who had helped me size a helm so that If anyone searches this topic again you have some suggestions, ( I was never one to enjoy paying dealer costs etc if I could help it).  Also agree with dont put just anything in there or you’ll be replacing a pump/seals. Etc. 

So, SeaStar steering fluid is a 15w hi vis hydraulic oil with rust inhibitors / anti oxidation mixed with it. Manufacturer was FUCHs Lubricants out of BC. Product code HA5430

There are brands suggested from SeaStar on their website that are significantly cheaper  in addition to any fluids meeting mil spec H 5606-G are also deemed acceptable. 
Seastar states to not use brake fluid!
Regarding ATF; for emergencies only and flush. Sorry I couldn’t get to the info other than a blank statement of ending up with Supertech (15w hi vis w/ rust inhibitors)  Just passing the information onward. You never know, it may not be about just the savings, you may be in a derby and pinched for time! Lol. 

[Andre wallyandre]

For the little needed I always use the real Seastar oil; personnal choice