• SeaStar Helm Unit Partial Rebuild (Teleflex)

    Thanks to GWNorth for contributing to this article!

    This guide will only cover installing new O-rings on the pressure relief screws for a 1986 SeaStar helm unit.

    On this particular boat gaining access to the helm pump proved to be very difficult. It required removing the instrument panel, ignition panel, trim panel and a lower access panel to gain access to the nuts on the back of the four bolts holding the helm pump in place.


    Click here to download the SeaStar installation guide.

    Attachment 587

    Once all of the bolts were removed the helm unit slid forward easily. If you are accomplishing a complete rebuild of the helm unit, disconnect the two hydraulic steering lines and you can completely remove the unit.

    Attachment 588

    Since we were only interested in gaining access to the pressure relief screws we left the steering lines attached. There are two pressure relief screws on the unit, one on each side. Warning these screws hold in a small ball bearing that is used to help meter fluid flow, when you remove these screws the ball bearing will fall out, do not lose it.

    Attachment 589

    The following picture shows the pressure relief screws removed. You can easily see the three o-rings that need replacing.

    Attachment 590
    Thanks to GWNorth for providing the picture below that shows the whole pressure relief assembly with the ball bearing and pressure spring. Be sure and read his comments at the end of the article regarding "o-rings" and adjusting the pressure relief screw.
    Attachment 773
    Once the new o-rings are installed, install the ball bearing and then screw the pressure relief screw all the way in. Now back out two turns and that should be a good starting point for adjusting the steering authority.

    Bleeding instructions will come with the rebuild kit. You can build your own bleed assembly by purchasing a quick connect pneumatic air hose fitting which fits perfectly in the threaded fill port on top of the reservoir. A piece of clear hose and the top off of a Lucas Oil Stabilizer bottle fits on the SeaStar bottle.

    Attachment 591

    To adjust your steering, turn your steering wheel full against the stops and if the wheel continues to move, tighten the pressure relief screw appx 1/2 turn. Continue this process until the steering wheel resist movement with the rudders at the stops. Accomplish the same procedure for the other side.


    Comments 6 Comments
    1. uwayguy's Avatar
      uwayguy -
      Hi....this is exactly what my problem is. I have been quoted by repair shops from $800.00 up to $1,500. to fix my steering. I finally took things apart myself and found the leak. It is the port side pressure relief screw, just as you described. Now, I just hope I can find where to get the O-rings and I don't mess up the install. This article has been a tremendous help and I just wanted to thank you.Dick
    1. TimG's Avatar
      TimG -
      Dick I am glad this helped you, that is what this website is all about! If you undertake any more projects on your boat feel free to take lots of pictures so you can post them here to help others out as well. No project is too big or small to put on here and there will always be someone looking for that information. We also welcome information not repair related, any tips-n-tricks that will help other boaters. I called Teleflex (Seastar) and they confirmed the part number for the rebuild kit. With that part number I searched on google and found it for a decent price. However I only used those o-rings out of the kit. You should be able to find those o-rings locally without any problems, try a hydraulics repair shop.
    1. uwayguy's Avatar
      uwayguy -
      Tim....Thank you for the aknowledgement and advice. The dealer has asked me for a part # or the SeaStar number on the helm pump just to be sure. Would you happen to still have one or the other. I noticed your rebuild was the upper helm. Mine is the lower. Will the pressure screws be the same. I noticed that I have an extra fluid intake that comes from the upper on the pump. Other than that they appear to be the same. Thanks again...Dick
    1. TimG's Avatar
      TimG -
      Dick I only have one helm station so it would be configured like an upper helm. My helm is a Seastar HH 5201 and was not covered in the charts shown here but you can see from this seastar guide here at the bottom of page 7 it shows the new part number for that kit to be a HS5151. However, uou need the part number off of the helm to be sure it is the same, there are several versions with minor differences.

      I am not sure but you may have the same steering for both upper and lower helms. The lower would just have a few more hoses. Check to be sure.

      You can do a google search for that part number and you will find the rebuild kits for around $30, don't forget to get enough fluid to purge the system.
    1. GWNorth's Avatar
      GWNorth -
      Hi Tim;I have performed a repair on my helm unit as well, and took some pictures along the way.A couple points that I'd like to note that might help somebody else.
      1. The o-rings for the pressure relief screws are standard -108 and -110 o-rings.
      2. The o-ring for the main shaft is a -214. A standard o-ring will suffice, however I did order -214 quad-rings as per specs. I have some extras in-case anybody else out there needs them.
      3. Prior to my removal of the pressure relief screws, I did a screwed them in all the way until they bottomed out and counted the # of turns along the way. When I inserted it with the new o-rings, I used that # of turns as a guide to put it back in again with some degree of accuracy.
      4. There was a "Punch" in the casing outside of the screw head that somebody needs to keep an eye on it.
      Attachment 757
      Attachment 758
    1. TimG's Avatar
      TimG -
      Great points GW, I added the picture of the pressure relief screw to the article and directed the readers to read the comments you provided. Thanks for the contributions.
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