Older Hynautics Controls

[Orient-Express]

I have a 1986 Bestway 50 with Hynautics controls at 3 stations. Was having trouble with no pressure in just the starboard shifter. For the life of me I couldn't figure out what the problem was, it seemed there was a blockage but it didn't make any sense where it could be until I ran into an obscure post on this forum by a PaulRainbow from 2016. I think it bears reposting for anyone who still has the Hynautics system. This saved me from having to replace a system ($$$$) that has become rather obsolete...at least for now.

"....Got this all sorted Saturday. The system has the MCV-04 charging valve fitted, this valve is shown in the fitting section of the manual, but is not mentioned in the section on bleeding the system. The manual just says to open the bleed screws. This will not work where the charging valve is fitted, no fluid is allowed from the reservoir to the slave cylinder. You have to turn the brass screw on the charging valve, that coincides with the circuit you are bleeding, half a turn or so to allow the fluid to flow, it then bleeds as it should."

As I said, this chance bit of information, one paragraph, saved me a ton of headache and expense. The post and the poster are no longer searchable it seems on YBW

 

[PaulRainbow]

I have a 1986 Bestway 50 with Hynautics controls at 3 stations. Was having trouble with no pressure in just the starboard shifter. For the life of me I couldn't figure out what the problem was, it seemed there was a blockage but it didn't make any sense where it could be until I ran into an obscure post on this forum by a PaulRainbow from 2016. I think it bears reposting for anyone who still has the Hynautics system. This saved me from having to replace a system ($$$$) that has become rather obsolete...at least for now.

"....Got this all sorted Saturday. The system has the MCV-04 charging valve fitted, this valve is shown in the fitting section of the manual, but is not mentioned in the section on bleeding the system. The manual just says to open the bleed screws. This will not work where the charging valve is fitted, no fluid is allowed from the reservoir to the slave cylinder. You have to turn the brass screw on the charging valve, that coincides with the circuit you are bleeding, half a turn or so to allow the fluid to flow, it then bleeds as it should."

As I said, this chance bit of information, one paragraph, saved me a ton of headache and expense. The post and the poster are no longer searchable it seems on YBW

There have been some changes on the forum that may have messed with the search feature for older posts, but i'm still here.

Really pleased that my post helped with your problem

 

[PaulRainbow]

If it helps anyone else, the original thread is here : Hynautic Engine Controls

 

[Orient-Express]

There have been some changes on the forum that may have messed with the search feature for older posts, but i'm still here.

Really pleased that my post helped with your problem

Can't tell you how grateful I am to have found that post in a Google search. Wanted to thank you for it.

 

[Bad1996]

Orient and Paul, I found Paul's post earlier and Orients post just now. Can one of you enlighten me a little more ? Maybe the orientation of the valve/s when bleeding ? I understand after moving the appropriate MCV-04 valve that you then were able to bleed. Did you move the valve back to the original location after bleeding ? I'm like Paul, I see nothing in the manual about the MCV-04 in the bleeding instructions. My scenario: spongy forward sender/shifter on the port side. Went to bleed at slave cylinder on transmission and one bleeder would dribble the other = nothing. Also the bleed screw at the shifter = nothing. I DID manage to make it where it would not go into either F or R therefore messing our weekend up lol. Note to self, work on boat at the END of the weekend, not the beginning.

 

[Bad1996]

Can't tell you how grateful I am to have found that post in a Google search. Wanted to thank you for it.

Here is an update option from Hynautic for the MCV-04. I'm still a little fuzzy on this. The manual shows the MCV-04 to have the newer style valves (pre- 1990). The housing on both will be the same. Mine is a 2001 SeaRay and has the MCV-06 valves. I don't know if it came that way or they were upgraded. Headed to the boat today to try bleeding again using the valves this time.
Update sheet: https://www.marineengine.com/produc...gTtQ_eHH_BAB-3R8-6aPE0UBnEqGEQNqFNnx2-GjD7Ug0
Picture of updated valves: https://www.marine-deals.co.nz/powe...6Yq47bN_C8HgFKoRel9qruzbq4PDmiNqL9PbgGH2xxL3o

 

[Bad1996]

Update for future reference for others: With the newer (updated) charging valves (link in my previous post) you do not need to move them to bleed the system. If you are not able to bleed fluid on one system (example: port transmission) the first thing to check is the o-ring on the top of the brass plug of a single charging valve. My port shifter was spongy in the forward movement and I was unable to bleed fluid from both slave bleed ports and also nothing from the shifter/sender bleed screw. The o-ring was distorted/large. Replaced it with a nice fitting general purpose o-ring, did the bleed procedure and all was fine. I had narrowed it down to the charging valve or the shifter piston. Made a tech call to MARINECONTROL.NET and he told me right away with a spongy shifter and unable to bleed, my problem would be the little o-ring. I think this is a small shop (maybe one man) and 100% if I need to send something out for a rebuild it will be to this shop in North Carolina !! Most likely save me at a minimum several hours and possibly way more trouble.