Hynautic Steering Fluid

[Native4]

Looking over the steering system in my "new" '01 motor yacht , I am fairly certain the previous owner was using a Dextron III ATF Instead of Hynautic fluid-- or even the Dextron II , type A, ATF called for by Hynautic .

I plan to purge the system when I can and remove the fluid and replace with Hynautic fluid MIL-H-5606 spec.

Does anyone know if the Dextron III meets the foregoing spec?

Making things a tad confusing is the fact that HYnautic spells it " Dextron" and Pennzoil spells is "DEXRON".


This makes it seem compatible:

"PENNZOIL® DEXRON®-III MERCON® provides superior wear protection for all passenger cars and light trucks requiring the use of a Type A or Type A Suffix A, DEXRON®, DEXRON®-II, DEXRON®-IIE, DEXRON®-III or MERCON® Automatic Transmission Fluid -- General Motors, Ford (other than M2C33F or Type F fluids), Chrysler, American Motors, Nissan, Honda, VW, Subaru, Mitsubishi, Isuzu, Toyota, Fiat, Audi, Alfa Romeo, Renault, Porsche and Mercedes Benz.

http://www.mil-specproducts.com/Docu...1118_PDS52.pdf
Thanks!

[MikeP]

IMO it's easiest to not be concerned about "compatibility" and just fill with 5606. The only possible advantage to using ATF is the fact that it's available anywhere. But I still have every bit of the 5606 I had left over in the can after I purged/refilled out system with it in 2005 so it's not like being able to pick up a can of ATF at the local parts store/gas station matters at all.

[Mike36c]

Your steering will tend to get stiff using ATF when the temperature drops, 5606 is the way to go and much cheaper than hynautic fluid. You can always add ATF in emergencies.

[Native4]

IMO it's easiest to not be concerned about "compatibility" and just fill with 5606. The only possible advantage to using ATF is the fact that it's available anywhere. But I still have every bit of the 5606 I had left over in the can after I purged/refilled out system with it in 2005 so it's not like being able to pick up a can of ATF at the local parts store/gas station matters at all.

OK. 5606 is readily available ?

[Native4]

Your steering will tend to get stiff using ATF when the temperature drops, 5606 is the way to go and much cheaper than hynautic fluid. You can always add ATF in emergencies.

OK. Thanks. Being in South Florida headed to Bahamas I am not too concerned about the low temps . . . . , but will replace the fluid with 5606 after my trip.

I assume it is easily obtained. Thanks.

[MikeP]

5606B is easily available at any place that handles aircraft parts/service or via the internet and is, as noted, much cheaper than hynautic fluid. Some good marine stores carry it - the marina parts place at Brittania Marina in Northport, NY had it on hand. I paid 15 bucks for the last gallon of it that I purchased. It was the Hynautic-recommended fluid for years until they started selling their own at 4x the price. You don't want Hynautic fluid for two reasons, IMO. One - it costs too much and, two - it's clear and harder to see leaks. 5606 is red, as God intended hydraulic fluid to be!

[Mike36c]

OK. Thanks. Being in South Florida headed to Bahamas I am not too concerned about the low temps . . . . , but will replace the fluid with 5606 after my trip.

I assume it is easily obtained. Thanks.

Aeroshell fluid 4 is also the same stuff, I'm not sure where you are but here in Stuart Lewis Marine Supply stocks it. I'm headed to the islands next month, can't wait!