Rebuilding Seastar HH5271-3 Helm Pump

Finally! It works! Got the new helm and installed it today. Also resealed the outboard hydraulic steering cylinder. So in the end, it was the cockpit helm that was the culprit. Most likely a bad check valve or shuttle valve. In any case, two brand new helms (one in the cabin, one in the cockpit), the resealed cylinder, and some hose work, I should be good for quite some time. The hose work involved removing the tees at the cabin helm where the cockpit helm tied in, and at the cockpit helm where the a/p smart pump teed in. Instead, I teed in to the main hose (between the cabin helm and the cylinder), under the galley countertop where my autopilot smart pump is installed. I ran a small branch hose off the mains, then hooked both the smart pump and cockpit helm into that. No leaks that I could see anywhere, and the boat steered as it should when I took it out for a quick test spin. I still have about an inch play in the cylinder if I push the outboard from side to side, but I suspect that is normal. Either that or some air hidden in the system somewhere. But I bled it today until there were no more air bubbles anywhere.
 
And here we go again. It worked, for a bit. But I'm right back to the same exact problem. I was thinking of checking my hydraulic hoses for any kinks to see if there was some restriction. But the more I thought about it, the more it seems this issue has to be in the helms. Low and behold I think I finally got a possible answer. I was going to post again on Hull Truth looking for some information, and when I logged on I found I had a private message. (If anyone knows how to turn on a switch to make Hull Truth notify me of new messages, please let me know.) It sounds reasonable, but I have not been able to find the part listed anywhere.

The symptom you are describing with your steering occurs on single engine boats with two helms at a similar vertical height. The unbalanced prop torque creates a positive pressure in the lines in one direction, and a slight suction effect in the other direction, which pulls the helm check valves off their seat a tiny bit. When you steer slowly enough to starboard the fluid can come back through the check valve of the second helm and return to the first helm through the compensation line. If you steer quickly you will generate enough pressure to close that second check valve and it will steer normally, as you've noticed. (You can also give it a quick snap, then steer slowly and it will work. That doesn't help your AP though.)


We've traditionally recommended Pro helms for this application, because they have a different check valve design that pressurizes the steering lines and keeps the check valves firmly seated. However, we are releasing a simple add-on kit soon that will work with standard helms. The kit part number is HA5500. It will take some time for it to percolate through distribution and be available at your local dealer (you probably won't be able to order one until closer to the end of September). I don't have pricing, but it will certainly be less than the cost of a new helm. Installation should take a marine mechanic no more than half an hour, including bleed time. There's no reason you couldn't do it yourself, but bleeding the system will be faster and easier with a power purge device that most dealers will have.


While it may seem that we are just trying to sell more stuff, this bypassing is a simple consequence of physics and isn't a defect.


Additional background FYI: If the second helm is much higher than the first (on a flybridge, say) then there is enough static head (pressure) in the lines to counter the suction effect, so we don't see this bypassing. It also doesn't happen on twin engine setups, because there is no unbalanced prop torque with counter-rotating props.
 
Or you can install manual cut off valve, or a two way valve--one way forward one way cockpit helm (capable of handling both Port and Sub. lines...

Interesting. I wonder if other C Dorys have this issue--most hellms are at the same levels.
 
Or you can install manual cut off valve, or a two way valve--one way forward one way cockpit helm (capable of handling both Port and Sub. lines...

Interesting. I wonder if other C Dorys have this issue--most hellms are at the same levels.
Click to expand...

KISS Bob. (Keep it simple). Why didn't I think of that. Well, initially reading your suggestion, I thought, sure, why not! And then as I started typing here I realized that frequently I'll go from one helm to the other to steer. Although not on plane. So maybe it would be worth my while to put the shut off valves in. I could leave them closed when operating on plane from the cabin helm, and open them when I'm operating at displacement speeds from either helm. I'll have to give it some more thought. I too wonder about the others that have dual helms.

I also wonder if I need to adjust my outboard's rudder trim tab a little more. The boat still takes more force to steer to port. That might correct the problem a bit as well. What setting do most folks have on their 150 hp outboards on a 25? Right now I've only got about 1 dot of trim set in towards the starboard. I may try setting that to 2 or 3 and see if it helps next season.
 
Wrote directly to Sea Star again to get some assistance. This was their reply:

Thanks for the email , if you have a twin helm system with a single ram we recommend PRO helms and if you have regular helms the HA5500 may be needed , adding a shut off valve in the return/compensation line is NOT advised . Any of our Authorized service center can convert the regular helms to PRO helms and eliminate the issue .

I wrote back stating I wasn't interested in spending more money on their more expensive helms and asked why they would recommend against the shutoff valve. This was their next reply:

The helms do not need to be replaced they can be modified by a service center to PRO by changing the rear cover , the HA5500 kit is sent out free of charge but the problem is we have no stock due to the pandemic and getting some machined parts . The HA5500 could be ordered form one of our service centers and it does not block the flow on the compensation line , it limits the flow and is set to allow full flow when needed .


I love runarounds. Interesting that their service centers would have these things, but the factory wouldn't. Of course I'm sure the service centers would be happy to send me out two free ones for my helm.... I do have an email out to one of the service centers listed on Sea Star's website. Wondering what they will reply.... Colby
 
Sea Star was bought out by Dometic a few years ago. Dometic service is ...often awful. Not sure if that will apply to Sea Star, but it will not be the company it was in the past.

They speak of not putting a shut off valve in the return/distributon line. That was not what I had in mind--although it might resolve the issue. I had meant valves in each of the in/out lines, not the return line of the outside helm. Then it would act as there was only a single helm from inside the main helm.

The part HA5500 does not come up in an internet search...so it may not be readily available. The Pro helm is only in the $500+ range--and I wonder if they have new ones of those?
 
Hi Bob. Yeah I knew you meant the pressure lines, but from reading the pm from the guy that claimed to be one of their design engineers and then the stuff from their official rep, I figured it might be easier to just put one shutoff valve in the compensation line. Last I checked the pro helms were a lot more expensive than the regular helms and also required higher pressure hoses which meant I would need to change out the entire system.
 
Putting in solenoid operating valves would be simple and easy to change. Some of the new "fly by wire" systems you have to change the station from the master, because they don't want someone who is a non crew member or authorized to take over the vessel. Many of the bigger boats have 3 to 5 helm stations. (Pilot house, Fly bridge, aft and both wings of bridge) The throttle and shifter are fly by wire, but steering is joy stick or a lever port to starboard. The auto pilot pump or remote often performs the steering function. I had one boat where I made a little sealed box, which had red and green buttons with direct connection to the relays on the autopilot pump.

The solenoid valve is not really under much pressure, if both are closed, unless you went hard over for some reason. Normally closed valves area available for as low as $18 each. You put a switch in at the aux helm, and turn that switch on when you want to steer from there. Rated at no more than 8 hours continuous use. Current draw about 1 amp, so 2 would be 2 amps, maybe a slight amount more...
 
And from one of the service centers, round and round we go...

Hi Colby,
I believe the HA5500 is a kit to convert the standard helms to the pro helm style valving, but I don’t have any other information on it than that. I have an e-mail in to Seastar about pricing and availability. We don’t have these kits in stock, and for liability reasons, we don’t sell the parts over the counter.
You could try the following places and see if it would be something they would have in stock.
Pier21 in Kenner, LA Pier21sales@gmail.com
Or Boat Steering Solutions in North Venice, FL Sales@boatsteer.com
Thanks,
Tim
Dan’s Southside Marine - Parts Dept.

I'm thinking the solenoid shut off valves would be the easiest way to go. At least I wouldn't need to pull the helms out yet again to service them. And I have pretty easy access to the hydraulic lines. I've tee'd in the auto pilot pump and the cockpit helm, under neath the sink area, which is just above the autopilot pump. I haven't started looking yet, but Bob do you have any links to the valves you know of? Thanks. Colby
 
Colby, this would be an experiment, but there are some in-expensive solenoid valves, normally closed on Amazon. (There are plenty of very expensive ones), but for your normal steering use, I believe that these would work)
For example
this would be in 1/8 or 1/4" pipe thread.

OrTwo for $28.

You want to be sure you get what pipe thread you want to work with fittings. Also be sure they are 12 V DC. The "experiment" is the pressure. These cheaper valves are rated 110 PSI to 140 PSI. The "back pressure" on the helm would normally be minimal. But if you put the wheel hard over and kept turning, you can generate pressure up to 1000 PSI. The valves are marked in flow direction--I would put the arrow toward the helm. They should work fine going each way, but designed to hold the rated pressure vs "atmospheric" on the down side. (or the pump side when used as "lock out".)

No, I don't think Sea Star would approve. It would be an experiment. You can buy valves for several hundred dollars which will handle 1000 PSI.

If you decide to go this route, we will communicate by PM, e-mail or phone.
 
Thanks Bob. I did see those but was wondering about direction and psi. I’ll have to give it some thought. I’d hate to lose steering and there is always the manual ball valves.
 
Finally decided to just install two manual shut off valves on the cockpit helm. Bob, I did do a little research into the solenoid operated valves, but looks like they need some pressure on them to work properly. And they require flow in only one direction. They may have worked in the end, but I just figured it would be more prudent to use valves rated for the max pressure possible. Won't know until spring if this fixes the problem, but I'm hoping it does! Colby

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Just a final follow up on this bleedthrough problem. The shutoff valves on the cockpit helm work great. When I want to use that helm, I just open them up. When through, close them. Have not had anymore issue with the cabin helm not responding to a slow or fast wheel turn! :) Colby
 
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