Re: Hynautic Parts Disappearing

[Juliet 15]

Re: Hynautic Parts Disappearing

After reading the thread about hynautics parts being scrubbed from the Dometic site, I took a look at my steering pumps (bridge and lower helm). There are no markings. I THINK these are hynautic helms, but no idea the model or type. Anyone recognize these? I'd like to get one spare replacement or a rebuild kit if I can ID these. Pics below.
Thanks in advance.

 

[motion30]

Looks like a sea star helm

 

[Keysdisease]

That may be a Hynautic helm. The 3rd line (return line) is an indication. Somewhere below deck you must have a reservoir which is a necessary part for these systems. Some reservoirs had integral hand air pumps, check if your works. If not get a bicycle pump or a 12v air pump and keep it aboard. Typically the first failure of a Hynautic system is loosing air, and loosing steering. If the cylinder fails, any brand cylinder wil work, a cylinder is a cylinder. If you are happy with the performance and turn # lock to lock, replace a cylinder with the same diameter as installed now, they all travel 7".

Given the age of these systems if your system does fail for something other than a leaking fitting or a cylinder failure, it might be time to consider Sea Star replacement.

 

[Juliet 15]

Thanks for your thorough reply. Yes, it does have a remote reservoir, up just behind the bridge helm. I'll look, but I don't think there's a hand pump attached. I think the reservoir feeds the helms by gravity.



You mention "...Typically the first failure of a Hynautic system is loosing air, and loosing steering." How do you mean losing air? I believe the system is supposed to be air free, yes? Taking the pics, I discovered the lower helm has evidence of a slight seep, coming from one of the fittings (haven't ID'd which one). I do not have any steering issues right now, but maybe the seep is a sign of pending issues.



Last question: There are 2 large diameter hoses attached to the large aluminum blocks on the back of these things, and then one small diameter hose entering the top (1) and the bottom (1) of them. I've assumed the large diameter hoses are the pressure and return lines. Any guesses what the smaller, tip and bottom lines are for (see pics above)?

 

[Portage_Bay]

If the reservoir is higher than the upper helm pump it may well be a gravity feed system. If it is lower, even by a small amount and has a pressure gauge then it is a pressurized system most likely Hynautic brand. Loosing air in the pressurized system can cause loss of steering. Oil leaking will also cause a loss of air pressure.

Regarding the hoses. The large hoses are the left - right pressure hoses. It's not a supply and return but a left - right shuttling back and forth as you steer. The small ones are the return lines. IF this is a Hynautic system.

1st determine by examining the reservoir if you have a Hynautic system. They produced two different styles of reservoirs. Both will be outwardly similar with the gold colored label and sight glasses. Both will have a pressure gauge. One will have the relief valve attached to the bottom of the reservoir as pictured in Keysdiseas's post. The other will have just fittings on the bottom, the relief valve will be elsewhere.

You are correct that there should be no air in the hydrauilic lines, helm pumps, ram and auto pilot pump. The only air in a Hynautic system should be in the reservoir. Oil should still show in the sight glasses.

It is important to know if you are dealing with a Hynautic system or not before getting too deep into the system. The bleeding protocol is a bit different.

Pictures would help in identifying your system.

Because your OP was about obtaining a rebuild kit I did some digging, I have a Hynautic system. Seems a good idea to be proactive in finding a kit. As of yet I have not found one. I did find that Seatech Marine Products will rebuild Hynautic helm pumps for $350. A reasonble price. With Dometic pulling support for Hynautic it's unsure how long Seatech will be able to get parts. When I get back to the boat I'll see if I can find model #s and contact them to see if I can order a kit.

If you find a source for kits please share your info.

 

[Keysdisease]

Portage is right on.

There is nothing "gravity" if this is a Hynautic system. The oil is pushed to the helms by the air pressure in the reservoir through the return line (copper in your photo.)

Lose air pressure, lose steering, hence the recommendation for a pump.

Since hydraulic steering became the norm in boats this size, there have been 3 brands that dominated the US market from the 70's until some other players came online this Century.

Teleflex had Syten and Capilano which became Sea Star
Hynautic was unique for being the only pressurized system
Wagner was strong in commercial, but some crossed over to recreational

Like Portage said, before you get in the weeds be certain to correctly identify what's aboard