Click for Northern Lights Click for Westport Click for MotorCheck Click for Ocean Alexander Click for Westport

Hynautic System trapped air?

Discussion in 'Technical Discussion' started by Bearzgirl, Oct 11, 2016.

You need to be registered and signed in to view this content.
  1. Bearzgirl

    Bearzgirl New Member

    Joined:
    Jun 2, 2016
    Messages:
    18
    Location:
    Michigan
    Hi All.
    My starboard side throttle lever seemed a bit spongy so I decided to bleed the system and apparently I'm doing something incorrectly. I bled the slave bleeders then topped off the reservoir and repressurized with air to 80 psi, bled to upper helm bleeder, refilled reservoir and pressurized to 80 psi again. When I cycle the throttle lever from idle position to full throttle and back to idle position (engine not running) the throttle lever wanders back up to almost full throttle position if I dont hold it down. Do I still have air trapped??? Or??
    Does the reservoir have an air bladder in it or is it just air over fluid that creates the pressure?? Any help is appreciated.
    Thanks, Steve
  2. Robertoman

    Robertoman Member

    Joined:
    Dec 15, 2010
    Messages:
    71
    Location:
    San Diego
    Yes, you still have air in the system. Don't be afraid to work the throttle between bleeding sessions to work out any air. You should bleed all the fluid from the reservoir under pressure at the slave, release pressure, and refill the resevoir and repressurize to 80psi+-. Work the throttle and bleed the bleeder valve at the control, (all the controls) you may need to repeat but eventually you will get all the air out. How old is this unit? might have wear in the slave piston or the O-rings.
  3. Capt J

    Capt J Senior Member

    Joined:
    Jul 11, 2005
    Messages:
    14,432
    Location:
    Fort Lauderdale
    Bleed from the flybridge controls.
  4. Bearzgirl

    Bearzgirl New Member

    Joined:
    Jun 2, 2016
    Messages:
    18
    Location:
    Michigan
    Thank I appreciate the feedback. I bled as you described but don't think I ran enough fluid thru the system or evacuated all of the air. My reservoir has the air chuck mounted on top of the reservoir fill plug so I assume there is no diaphragm in the reservoir between the air and fluid, so this means its just air on top of the fluid?? Just curious.
    You also mentioned doing all the controls, I wasn't having any issue with the port side , only starboard so you think I may need to do both sides ?
    Thanks again,
    Steve
  5. Capt J

    Capt J Senior Member

    Joined:
    Jul 11, 2005
    Messages:
    14,432
    Location:
    Fort Lauderdale
    It could also be a bad actuator. If the resevoir went too low while bleeding everything, you'd have to start over.
  6. Robertoman

    Robertoman Member

    Joined:
    Dec 15, 2010
    Messages:
    71
    Location:
    San Diego
    Capt J is correct in referring to what I had called the slave, is actually called the actuator. I believe Capt J has previously commented on bleeding procedures elsewhere in this forum. He is the expert.
    I should have been more specific about bleeding. If you have problems only on one side, generally that side (port or starboard) is all you need to mess with. However if you have more than one control (flybridge, cockpit, etc), it can't hurt to bleed all the controls on that side using the allen plug on the control behind the lever. Usually just a small amount of air comes out at control.
    There is no diaphragm between air and hynautic fluid.
  7. Bearzgirl

    Bearzgirl New Member

    Joined:
    Jun 2, 2016
    Messages:
    18
    Location:
    Michigan
    Thanks again guys. I only ran the reservoir down to about half full then depressurized, filled and re-pressurized so it sounds like I need to run a lot more thru it and bleed a bit more. The problem is on my Starboard side only and I have one set of bridge controls (48' Viking Conv) so I'll give it another try. Im surprised there's no diaphragm between the air and fluid, but Im sure there's a good reason. They sure didn't make it easy to fill that reservoir, its buried in the corner under the bridge console in the far port corner and Im not 5'-0" and weigh 110 lbs!

    Steve
  8. Bearzgirl

    Bearzgirl New Member

    Joined:
    Jun 2, 2016
    Messages:
    18
    Location:
    Michigan
    Good Morning All,
    I had a little time to work on the air bleed this weekend and it was unsuccessful so Im not sure what I may be doing wrong or if there's another underlying issue. I disconnected the slave arm on the starboard engine, filled the reservoir, pressurized to 90 psi, opened one of the slave bleed ports moved the slave arm while I bled some air until it was a steady stream of fluid and closed bleed valve. Did the same on the second bleed port on the slave then went up on the bridge, opened up the bleed valve and pumped the throttle arm and only got a spit of air / fluid, no steady stream of fluid so I continued to pump the lever and still no fluid. I checked the reservoir and it was about 50% full so I topped it off, re pressurized and tried pumping the throttle again, still no fluid, WTH? So I went back down and dbl checked the slave bleeders, re bled them and only air came out when I cycled the slave arm, barely any fluid out of either bleeder so am I missing something?? If theres 90 psi on the system shouldn't fluid come out on its own without cycling the slave arm or throttle arm or is there a chance that the filter on the bottom of the reservoir is plugged and not allowing the system to be charged completely?? Do I need someone at the helm pumping the throttle arm while Im bleeding the slave vs me cycling it by hand down below? Any suggestions are appreciated.

    Thanks in advance,
    Steve
  9. Capt Ralph

    Capt Ralph Senior Member

    Joined:
    Sep 8, 2004
    Messages:
    12,649
    Location:
    Satsuma, FL
    The only time I have worked on this stuff, the owner had the manuals. The install manual made better sense bleeding the system than the service manual. The service manual covered theory in better detail.
    If I remember, the throttle never felt rite our first attempt. Weeks later he came back and we tried again. More air out at the engine and when we opened that lil allen screw on the side, an air geyser, then perfection. Only that screw was opened on the top. Manuals are important.
    Two person job IMO.
    Blue Marlin likes this.
  10. Robertoman

    Robertoman Member

    Joined:
    Dec 15, 2010
    Messages:
    71
    Location:
    San Diego
    The only reason I know anything about Hynautic is because I just recently went thru the same learning process that you are going through.
    1. The pressurized reservoir will cause fluid to work thru the whole system without moving the levers, at least that's what the book says!
    2. Are you using the correct fluid?
    3. Hynautic has been aquired by Seastar and has all the manuals under "support".
    4. Parts are easy to find on the internet.
    5. rcrapps has some good points
    Hope some of this helps
  11. T.T.

    T.T. Senior Member

    Joined:
    Jan 22, 2010
    Messages:
    92
    Location:
    S.F.
  12. Bearzgirl

    Bearzgirl New Member

    Joined:
    Jun 2, 2016
    Messages:
    18
    Location:
    Michigan
    Thanks Again Guys. The bottom line is its a two man job and I need to bleed a lot more thru the system, the manual is very informative so thanks for that. Best part of trial and error is that once you get it you never forget it! To Robertoman, yes, I'm using a 50/50 mix of distilled water and ethylene glycol with80-90 PSI on the air.
  13. Capt J

    Capt J Senior Member

    Joined:
    Jul 11, 2005
    Messages:
    14,432
    Location:
    Fort Lauderdale
    It shouldn't be a 2 man job. I've always been able to bleed them with 1 person. Generally unless the entire system has been taken apart, you only need to bleed the highest station. And, generally just loosen the bolt till you get solid fluid, close it up work it a couple of times and bleed again and done.

    You have a bad actuator and no amount of bleeding is going to fix it. I also would use the glycol mixture sold by hynautic rather than mixing my own. I don't know the exact concentration it is but it seems (feels/looks) like a lot less than 50/50. Follow the manual if it says to use something other than their own mixture. Also the can and other parts are Aluminum, the wrong ethylene glycol mixture will start attacking them. There is also a screen in the bottom of the can where one of the hoses hook up, I've seen this get nasty with debris over the years and cause the hynautic to get more stiff and stuff...... but the fact that the shifter handle is going back when you press it foward, tells me the actuator is stuck and the fluid cannot push the actuator foward, so the pressure you just made by pushing the shifter foward is pushing itself right back. In very rare instances it can also be a hose that is going bad and blocking on the inside.
  14. Bearzgirl

    Bearzgirl New Member

    Joined:
    Jun 2, 2016
    Messages:
    18
    Location:
    Michigan
    Captain J,
    The system wasn't taken apart entirely by the previous owner, he just let me know that the throttle was a bit spongy as a courtesy so I decided to bleed it toward the end of the season just incase it didn't go as planned so I made the right call on that one. As for the glycol / water mix I got that info from another site or manual that listed Prestone ethylene glycol as an acceptable fluid for the Hynautics system, I'll try to find and share. You mention that the bleed should be done at the upper helm which I would agree but when I removed the bleeder nothing came out which seemed odd especially when I had 80 psi on the system, I would think the whole system is under pressure. Does the synchronizer come into play on this or maybe like you mentioned the filter screen on the bottom of the reservoir is plugged?? It just doesn't seem Im getting a completely pressurized system even when the tank is full and under pressure.
  15. Capt J

    Capt J Senior Member

    Joined:
    Jul 11, 2005
    Messages:
    14,432
    Location:
    Fort Lauderdale
    If you're not getting any fluid coming out of the upper helm, you have a major issue and it isn't bleeding.....could be a pinched line (rare), most likely the actuator is frozen and needs to be replaced..... could be the helm unit itself, but doubtful. You have a major issue that needs to be fixed.
  16. Robertoman

    Robertoman Member

    Joined:
    Dec 15, 2010
    Messages:
    71
    Location:
    San Diego
    Bearzgirl ,
    ReRead, what Captain J said about the screen in the line below the reservoir being plugged, if that is not it, not replace the slave.
    I would be willing to bet one of those is the problem.
    You will see a good schematic of the screen in in the bottom of the reservoir in the link that T.T. provided.
    P.S. bleed at the slave first, last at the control.
    Next replace the throttle control!!!
  17. T.T.

    T.T. Senior Member

    Joined:
    Jan 22, 2010
    Messages:
    92
    Location:
    S.F.
    Look in the bottom of the reservoir and see if there is any sediment or debris. If yes, there is a good chance the system is contaminated. The tolerances on the double pilot check valve inside the slave are minimal and the contaminated fluid will corrode the moving parts and seize the valve.
    If this is the case, replace the slave and completely flush the system with distilled water until all bleed valves produce clean water. Fill and bleed with manufacturers fluid.
  18. Bearzgirl

    Bearzgirl New Member

    Joined:
    Jun 2, 2016
    Messages:
    18
    Location:
    Michigan
    Thanks Again Guys,
    I have my long time mechanic who has worked on these systems meeting me this weekend to go thru the system from top to bottom, literally, so we'll be looking at all points you guys have brought up. I usually don't bring him on board unless I'm at wits end and cannot fix myself. I believe you guys have helped me narrow it down to the bad slave or plugged reservoir outlet and in my opinion, not much else would make sense. I followed the hoses from start to finish and there are no pinch points, the level is full, the pressure is right but no flow so its either plugged or the slave is hung up. The worst part of this is we're having a great fall here in Michigan so Im missing some great boating weather!
    I'll let you know what we find and post the update so hopefully it helps the next guy that runs into a similar issue.
    Steve
  19. Bearzgirl

    Bearzgirl New Member

    Joined:
    Jun 2, 2016
    Messages:
    18
    Location:
    Michigan
    Here's my latest findings and update,
    Tried one more time to bleed, got nothing but air sooo we started at the source and removed what I call the distribution block thats fed directly from the reservoir and pulled one of the flow control valves. Theres four of control valves with set screws that set the travel of the small plungers in each valve which in turn regulates the amount of flow that goes thru them, at least thats my interpretation. I noticed the small weep holes had some clear debris in them, a couple were plugged entirely so I took the whole assembly apart and cleaned thoroughly. At this point I removed the reservoir and removed the filter element, LOTS of what looked and felt to be silicon deposits (see pics) and that was my ahaa moment, the previous owner / mechanic didn't follow Mfg'rs recommendations to NOT use a ethylene glycol with silicates!! It was so packed you couldn't even blow thru the filter so that explains no fluid up at the bridge or lower bleed valves, I must have bled whatever fluid that was trapped in the system. I spent the better part of the morning cleaning / soaking all the parts which are now ready to re install. The plan is now to flush / bleed the heck out of the entire system with distilled water to hopefully remove any remaining deposits that may have made their way into the system. I cannot say if this is all of the problem yet but it will most certainly help the operation.
    Steve IMG_6515.JPG IMG_6526.JPG IMG_6528.JPG IMG_6553.JPG IMG_6555.JPG IMG_6515.JPG IMG_6526.JPG IMG_6528.JPG IMG_6553.JPG IMG_6555.JPG