Fluid in hyd. steering - The Hull Truth

stingwray · 12-15-2008, 06:37 PM

Is Sea star hyd. oil and Dexron III compatible? In the process of replacing hyd. steer cyl. on the boat and the fluid is red like Dexron trans. fluid. The unit is about ten years old and i am not sure which type of oil is in the system. If you were replacing the hyd. steer cyl. what fluid would you put in the system and why?
Thanks

high'n'dry · 12-15-2008, 06:43 PM

No, the fluid is Mil Spec aviation hydraulic oil, 5606. You may also use the Sea Star oil which is a clear yellow. The other fluids may damage the seals.

kerno · 12-15-2008, 07:34 PM

I have to say that I have been using ordinary hydraulic fluid, including Dexron, for years without problems. The SeaStar fluid does comply with avaition specs, so perhaps its lowered flammability reduces the chances of your steering system bursting into flames. I honestly feel it just lightens your wallet.

carbo · 12-15-2008, 07:39 PM

I have used ATF DexronIII in all my seastar systems with ZERO problems, and it mixes fine. If you want to pay 8 times more for their fluid have at it. I mean crap. they start dripping after a few years no matter what fluid you use. Do a search this has been debated dozens of times.

My Turn · 12-15-2008, 07:45 PM

I use hydraulic oil from Napa at about 2 bucks a quart. No way I am paying the "marine tax" of 8 bucks a quart for the seastar stuff. Been working fine for a year.

Justin_NJ · 12-15-2008, 08:07 PM

8 bux a quart for seastar, where can you get it for 8 dollars. It's about 16-18 in most stores i've seen.

conehead39 · 12-15-2008, 08:34 PM

1.Sea Star clear expensive.
2.Mil spec 5606 aviation hydraulic fluid but much cheaper.Purchase at various aviation parts houses.
It has a red dye. 1+2 are thinner in viscosity compared to Dexron.
3. Dexron has red dye also but about equivalent to 10-20 weight SAE.
Therefore,will take more effort to turn the helm,especially in cold weather.

All 3 are compatible as far as seals go.
You can mix or use seperately.

Have Used Sea Star , mil H-5606, and Dexron exclusively and also various mixtures for over 25 years. No helm pump or ram cylinder failed from above useage.

See ,,,,,Sea Star website about Dexron

If you are 30 miles out and loose steering then add Dexron or motor oil. EMERGENCY.
You can purge it later.

prowlersfish · 12-15-2008, 09:02 PM

I would use the seastar oil you got a system that cost a grand . what is 16 bucks ? how often do you need it ? atf is ok in a emergency but it can make the steering stiff in cold weather .

1NO REGRETS · 12-15-2008, 09:33 PM

I was told long ago when I had a hynautic helm with the canister that had air pressure in it, to use type-f fluid.I have used it ever since.I have used it in my dual seastar system when bleeding the system for ten years.No problems .I would think especially in warm climates thicker fluid would be better, and maybe have less leaks?!

I know that every time I buy some type- f the guy looks at me weird.Says that was for the old style ford transmissions.I just say o.k and go on my way.Many A BOAT has had transmission fluid put in the helm when set up and no one knows the difference.Past mechanic"friends" have said thats what they used when rigging a new boat

But it was the dextron2 or 3 ,bottom line is I don't think it matters much.The seals don't know the difference, so it seems.

whays · 12-15-2008, 10:30 PM

I just resealed my Sea Star cylinder and refilled with ATF. The motor steers easier than ever. I pretty confident that the ATF will be fine.

yottyboy · 12-16-2008, 06:38 AM

You don't want anything that's incompatible with the o ring seals. I spend the extra bones for the Seastar stuff since it's what they say to use. Like someone else said, what's 17 bucks in the grand scheme?

cWICKBERG · 12-16-2008, 07:25 AM

Quote:

yottyboy - 12/16/2008 8:38 AM You don't want anything that's incompatible with the o ring seals. I spend the extra bones for the Seastar stuff since it's what they say to use. Like someone else said, what's 17 bucks in the grand scheme?

I had a problem last year when my "dealer" fixed a small leak in my steering...It continued to leak and he flushed the system and refilled with ATF...Then the system really started leaking and I went to the Seastar Website...It specifically said NOT to use ATF except in an emergency.

TMALSS, I had to replace the seals in the cylinders, flushed the system and refilled with Seastar Fluid...no runs, drips or errors...

The dealer paid me for materials and I did the work myself.

I too, used to use ATF in my older Hynautic system with the reserve tank and all, because they said you could...

Steering is a real critical function for you boat...It doesn't take much of a leak in the system to let air in and start causing problems with steering...Why not use what is recommended by the manufacturer? I have a gallon of the Aviation fluid that I keep on hand...It was $15 for a gallon

1NO REGRETS · 12-16-2008, 07:33 AM

Just telling you the real world facts.I have been using atf for ten years ,have two, two seastar rams and zero problems.Could be that what you were able to purge or repair was the problem not the fluid.Oh. forgot, my autopilot has been inline all of those ten years as well

.

cWICKBERG · 12-16-2008, 07:46 AM

Quote:

1NO REGRETS - 12/16/2008 9:33 AM Just telling you the real world facts.I have been using atf for ten years ,have two, two seastar rams and zero problems.Could be that what you were able to purge or repair was the problem not the fluid.Oh. forgot, my autopilot has been inline all of those ten years as well

.

Glad to hear you've had no problems...I think it is generally one of preference...I think there is an issue with mixing the two and one of warranty if you have a new system...

They both generally perform the same function...I think the viscosity on ATF is slighty less viscous than the MilSpec fluid...

seahorse · 12-16-2008, 08:02 AM

ATF is not recommended by Teleflex as it is thicker and causes stiffer steering. See the Teleflex website or read the instructional booklet that comes with each steering product.

conehead39 · 12-16-2008, 08:23 AM

Synthetic Dexron 6 is used in the new GM transmissions. It is backward compatible w earlier Dexron fluid. Should work better in cold weather compared to earlier ATF .
They even sell Dexron 6 at Walmart.

I don't know the viscosity index of Sea Star ,Dexron III , or Dexron 6.
Synthetic oil flows better at low temps.

matt_unique · 12-16-2008, 08:44 AM

I echo the comments of others, use the Seastar fluid to avoid the risk. It's cheap considering the cost of your steering system.

Justin_NJ · 12-16-2008, 03:17 PM

I put seastar in my current boat, but actually on my last boat before I knew any better, I actually used power steering fluid and didn't have any problems at all. Worked fine! I think I will stick to seastar for now.

conehead39 · 12-16-2008, 08:36 PM

Sea Teleflex sea Star fluid reqirements..
The fluid must meet Mil Spec 5606c.... Teleflex spec

http://ww2.seastarsteering.com/OUTBO...ED/Fluid.htm&1

Pike Oil Comp in GA sells 5606 for $15 per gal. H is better than C or A.
http://search.store.yahoo.net/cgi-bi...m/nsearch.html

however 5606 has a red dye ;;; deemed by the military to distinguish it from engine oil and other oils.

I know of one boat mfg that buys red 5606 by the 55 gal drum to service new hydraulic steering systems..