It’s time for a hynautic transmission bleed, I think

[The Brockerts]

It’s time for a hynautic transmission bleed, I think. All controls (throttles and starboard transmission) work well. The PORT transmission is very soft, doesn’t stay in place and as I was played with it yesterday would not go into reverse. I disconnect the hynautice slave from the transmission lever. Then I was able to work the transmission lever just fine. Felt solid clicked into place, springs and mechanicals all worked as I expected. I’ve never bled any system like this so the closest I can come to is bleeding brakes on a car. Seems like the same principals would apply. Dug through the TF with search’s and didn’t find much on the topic. The web and seastar provided a manual with bleed process described. From that doc and diagrams http://www.seastarsolutions.com/wp-content/uploads/2011/06/182042C.pdf I’m building my plan. Several questions come to mind. Step 2 page 15, talks about opening the bleeder value 1 turn. Now it seems like I’ll have fluid spraying out given there is about 100psi sitting on the other end that. Getting that cap off and getting a 5/16 tube into it seems like a mess is going to happen. Seem like there is a good possibility to spray this fluid everywhere. Do I open both bleeder values at the same time, or one at a time? I need to be moving the handles for this process to. I’ll have to track down the tape nomenclature. Seems to be one tape line return? 2 tape line the send? Also, I’ve attached a picture of a manifold. Anything this is used for in this process? Can I just bleed the one line without effecting the other lines? Any words of wisdom?

The Brockerts

 

[Lepke]

Another way to bleed is with vacuum. Starting with the bleed fitting closest to the reservoir, attach a powered or hand pump like the one shown. A small see thru plastic container collects the fluid and lets you see any air bubbles. Work your way thru the bleed fittings. That way you get about 95% of the air out. Then under operating pressure, open the bleed valves with a rag under or around the bleed valves to catch any fluid. Takes 2 people, one bleeding and one operating the controls.
But, since the system is mostly free of air now, you probably can just use the system pressure generated by operating the controls, and go thru the bleed ports with a rag and not make a mess.

 

[The Brockerts]

Hmmmm, just a rag and open the ports a little, seems to easy, and nothing on a boat turns into something easy....LOL

The Brockert

 

[DCDC]

Before you bleed:

The ‘anything this is used for?’ in diagram 3 is an isolation valve manifold. If the valves (screws) are closed (they should be) the throttle/gear circuits are isolated from the pressurized fluid reservoir. This prevents the reservoir from emptying if there is a leak. Over time small, insignificant leaks will depressurization a circuit resulting in dead or mushy control. I have never found this mentioned in any Hynautics documentation. Maybe lost for older systems when Hynautics was purchased by Seastar.

Try opening the valves/screws for a moment which will re-pressurize the circuits (if there is fluid and pressure in the reservoir). I have an older Hynautics system and had the same problem. Bleeding made it worse but re-pressurizing resolved the problem. Now I open the valves every few months to maintain crisp control.

Check for fluid leaking from seals at the helm controls and at the actuators. If significant then the seals need to be replaced. Currently I have a small, intermittent leak at one of the gear controls but it’s not enough for me to attempt a seal change. My reservoir loses about 1/4” of fluid and 10 psig over a year.

I was also advised to slowly work the controls back and forth several times before starting the engines, especially if the boat has not been used for a while.

Good luck. Let us know what works and what does not. Thanks.

 

[The Brockerts]

I've not found any leaks, at least in the engine room. I now realize I need to check under and around both helm controls.

Isolation valve manifold. So actually under normal conditions this "device" is isn't even in play? I thought it had to have pressure for everything to work. Learn something new everyday.

The Brockerts

 

[Woodland Hills]

If you still have shifting or throttle issues after bleeding then you may have a breakdown of the glycol used in the system. After a few decades, even sooner if anti-freeze with all its additives is used instead of pure glycol, a waxy substance forms in the fluid and clogs the valves making them stick. Flushing the system will not remove this and the only cure is to replace the valves and controls or remove, disassemble and clean them.

I was told this by two different Hynautic techs, one in Florida and one in the Chesapeake Bay, when my shifters began to misfunction occasionally. A system flush and fluid change made no difference and now I just shift by moving the levers as hard and fast as possible to move the fluid as strongly as possible. A smooth soft movement of the shifters is more likely to fail to shift than a rapid firm movement.

My system calls for 80-85 psi minimum and I try to keep it there when it is cold: a cold boat will have lower pressure than after it has run for a few hours. I use a bicycle tire pump to service the air pressure. If you are losing pressure and you cannot find any fluid leaks replace the Schrader valve and always keep the cap on the valve. If you replace the valve and pressure still drops then replace the pressure gauge. Both the valve and the gauge will leak air, not fluid, and will not give any indication of leaking.

 

[The Brockerts]

DCDC,
Thanks for the comments, your suggestions worked great.
When to the upper helm, and opened the bleeder value, air bubbles came out with a few drop of fluid. Closed it off. When below and opened the isolation value. Went back to the upper helm and opened the bleeder value again, just a little bit and very slowly, more bubbles and fluid started to come out. Closed it off and tested everything. It's feels good and works great.

Thanks again
The Brockerts

 

[DCDC]

You’re welcome. Glad it worked for you.