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Hynautics Fluid

Discussion in 'Viking Yacht' started by Bearzgirl, Sep 15, 2016.

  1. Bearzgirl

    Bearzgirl New Member

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    Jun 2, 2016
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    Michigan
    I've got a '88 Viking Convertible which has the Hynautics Steering, throttles and transmission controls and my question is what is the correct fluid to use in these systems. I have heard you can use ATF transmission fluid or coolant / anti freeze so is there a recommended fluid to use or are either acceptable?
    Thanks in advance,
    Steve
  2. baltimore bob

    baltimore bob Member

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    I heard from someone I believe that using the wrong fluid will do damage to the seals. I'd bite the bullet and get the right stuff. ( Hynautics branded fluid)
  3. Pascal

    Pascal Senior Member

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    I woudlnt use coolant but the Hynautic literature states that ATF is fine although if may result in stiffer steering. I ve been using ATF in a power steering Hynautic system for 8 years no issue.
  4. Capt Ralph

    Capt Ralph Senior Member

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    In an emergency anything can be used. For normal operation, there may be substitutes.
    But why differ from the factory specs on something that has a very low service interval.
    The fluids are on the shelf at West and other stores, Yes it cost a lil more, but why guess at what works when you can get the real factory product from a same/common retail shelf?

    In the service we provide, If there is a factory spec, it gets that product.
    When we offer estimates & scopes of work, factory specs are noted and adhered to.

    When there is any performance, warranty & support issues; We know everybody involved is on the same page and answers & support is easier to achieve.
    Last edited: Sep 15, 2016
  5. Capt J

    Capt J Senior Member

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    In the steering use Hynautic steering fluid. I've seen people use both ATF and AW 36, but I use the Hynautic branded stuff.

    The controls (throttles and shifter) get Hynautic ethelyne glycol. I too use the Hynautic branded stuff here too.
  6. Bearzgirl

    Bearzgirl New Member

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    Thanks guys, I appreciate the feedback.
    Steve
  7. T.T.

    T.T. Senior Member

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    Jan 22, 2010
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    S.F.
    The Hynautic throttle and shifter assemblies employ a double pilot check valve with close tolerances. I've seen the valves pitted and the reservoir body
    severely pitted, likely from additives in anti freeze. The Hynautic fluid is 50/50 glycol-distilled water.