Hynautic System trapped air?

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

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

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

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

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.

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.

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

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