Practice Bleeding, with Hynautic Seastar

[markrkrebs]

My tranny has Hynautic controls with dual pressurizing / charging manifolds. (1985 Tolly 61'). I spent the weekend trying to bleed it.

* There are two charging manifolds (8 lines) so the fwd and reverse lines are pressurized for each transmission, between the slave cylinder and the controls abovedecks. I think this all but precludes a complete purge when bleeding: the top half of the system will never feel a pressure differential, so the fluid will not circulate around. As proof, bleeding from the slave, I can run quarts of clean bubble-free fluid through but still have air up top.

* Ok, so I'll bleed it from the top, I thought. No luck. In one direction it'll bleed but in the other, it's open: no fluid flows in or out. What??? (I think this may mean stuck charging poppet in the reverse half of the leg.

* I say their mechanical drawing (see attachement) has several errors, most egregious the check ball and spring swapped in their positions. And second it's not an interference fit between the brass valve body and aluminum plug, and third the threads in the plug are not so long as to impede flow around the brass valve body. ...and these are all diabolical errors in understanding the damn thing when you're in the bilge at anchor far from succor with radiator fluid all over you.

Any comment? or help?

 

[Rsysol]

My tranny has Hynautic controls with dual pressurizing / charging manifolds. (1985 Tolly 61'). I spent the weekend trying to bleed it.

* There are two charging manifolds (8 lines) so the fwd and reverse lines are pressurized for each transmission, between the slave cylinder and the controls abovedecks. I think this all but precludes a complete purge when bleeding: the top half of the system will never feel a pressure differential, so the fluid will not circulate around. As proof, bleeding from the slave, I can run quarts of clean bubble-free fluid through but still have air up top.

* Ok, so I'll bleed it from the top, I thought. No luck. In one direction it'll bleed but in the other, it's open: no fluid flows in or out. What??? (I think this may mean stuck charging poppet in the reverse half of the leg.

* I say their mechanical drawing (see attachement) has several errors, most egregious the check ball and spring swapped in their positions. And second it's not an interference fit between the brass valve body and aluminum plug, and third the threads in the plug are not so long as to impede flow around the brass valve body. ...and these are all diabolical errors in understanding the damn thing when you're in the bilge at anchor far from succor with radiator fluid all over you.

Any comment? or help?

Hi, did you ever get help on this issue? My shift controller has gone soft, trying to bleed does nothing but make it worse. I’m going to have the R-13 rebuilt since I cannot operate the valves on the charging manifold.

I agree, poor documentation and since they are discontinued, I’m not sure if we’ll get any better info.

 

[Portage_Bay]

I can't speak to the Hynautic engine / trans controls. However I do have Hynautic steering, 83 vintage. I learned that Seastar bought Hynautic. Dometic bought Seastar. Working my way through the Dometic support system I found a tech who was very familiar with the older Hynautic systems and was a great help. Give it a try.

Sent from my SM-T500 using Trawler Forum mobile app

 

[markrkrebs]

help bleeding

I can maybe help. "Gone soft" very likely just means air in it. You should wonder about that, but bleeding should solve it. The procedure dosen't clarify well that you have to make sure you get all the air out, and *that* means the flow has to go from the reservoir both ways through the circuit to blow the bubbles out at the servo bleed valve. Finally clearing the last bits out of the high end can also come out of the sender. You have to move the levers to the stops to release the little bicycle poppet valve and (for me) it was absolutely key to get a tight fitting tube into the bleed port and running into a big (quart) container of fluid so that if you develop any suction (eg when moving the lever, it will siphon fluid back in, instead of sucking in air. That was the procedure that finally solved it for me.

 

[markrkrebs]

There are no valves (that you turn) on the charging manifold. Those aren't meant to be turned. Instead, poppet valves inside there will open automatically and let pressurized fluid in from the reservoir when you crack a bleed screw somewhere. You should get a flow through the system, accumulating fluid in your catch-basin and seeing the level go down in the reservoir sight glass: that proves it's working. If you've cracked those manifold "valves" that would be a mistake (that I've made, too) because it will admit MORE air to the system. I also had wrecked the tired old o-rings that sealed those to the manifold body. I fixed it (temporarily) with a rubber band, and ordered some new poppet assemblies. I'd recommend that. "Rebuilding" the manifold can't be much more than replacing those valves & o-rings.

 

[Rsysol]

Good point, I've been attempting the bleeding, but I get no flow at the servo (the shifter, the throttle is fine) and only air at both the helm and flybridge senders. This has been a bulletproof system for me, 10 years without touching it outside of repressurizing once, I've never had to add fluid. I'm learning.

Unfortunately, the reservoir has been leaking just a bit so I'm going to bite the bullet and rebuild and do the full bleeding procedure afterwards. Your suggestions are solid and I just purchased the bleed parts from Dometic to do it right (hopefully).

 

[Mjohnson]

Recently finished fighting Hynautic controls issues. The system is pressurized to bleed you Crack the bleeder at the servo fluid will flow. If not go to the manifold pull the poppet valves and clean the screen thats in there. The final bit of air will be bleed at the senders. Don't worry about the o-rings they are all standard sizes any hardware or chandlery should have. One final note the bleed valve inside the senders is to sync multi station controls. It is a standard Schrader valve from a tire valve stem