SeaStar Hydraulic Bleeding

Repair or modification of Boston Whaler boats, their engines, trailers, and gear
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SeaStar Hydraulic Bleeding

Postby dtmackey » Sat Jul 06, 2019 10:28 pm

Due to then hose routing in some boats with high and low points, it can be difficult to bleed a hydraulic steering system. On one of my boats, I experienced this problem. No matter how many times I used the setup from Teleflex with the two fluid containers and trying to bleed air, I could not get out all the air, and the steering still had a small dead spot.

I wanted to share a bleed system I made from stuff kicking around the house:

  • a jug with thicker than normal plastic walls
  • 5/16-inch and 3/8-inch ID hoses
  • T-fitting for outboard mounted steering cylinder bleed fitting hoses
  • two brass fittings to screw in the jug
  • epoxy to put around the two brass fittings after installation in the jug bottom
  • screw-in fitting for the SeaStar helm

Fig. 1. The jug bottom with two fittings installed and epoxy reinforcement.

Fig. 2. Two hoses are connected to the bleed fittings on the steering cylinder and combined at a T-fitting. The line from the T-fitting runs back to the suspended jug in Figure 1.

The jug is suspended and one-quart of hydraulic fluid is added to the jug. If necessary, more fluid can be added. The system (very nicely) does not use two separate jugs, one for supply reservoir and one as a bleed overflow catch reservoir. One jug serves both purposes.

The steering wheel can be kept turning and turning to get out every bubble. And the best part yet: the bleeding process can be accomplished with just with one person and without worry about air being introduced into the system.

Fig. 3. The system.

Fig. 4. Once the setup is cleaned of steering fluid, it stores nicely if needed again.

If the hydraulic fluid is water-free but looks dirty, it can be run through a filter and reused.


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Re: SeaStar Hydraulic bleeding

Postby jimh » Sun Jul 07, 2019 12:28 am

You have a very crafty solution to a common problem.

The last time the hydraulic steering on my boat was opened and needed the air bled out, a Teleflex power-bleeder system was used. After bleeding air with the power bleeder,the steering was more solid and free from any loose spots than it had ever been. Careful bleeding of air from the steering really helps. I think your system is a very good solution.

Does the fitting on the jug bottom for the return line to the jug have an extension inside the jug to raise it to a higher level than the output fitting?

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Re: SeaStar Hydraulic bleeding

Postby GoldenDaze » Sun Jul 07, 2019 6:23 pm

I laughed out loud because of how brilliant this idea is! What a time-saver. My only concern would be that when I installed my hydraulic steering and bled it, I had millions of tiny bubbles in the bleed output that took quite a few minutes to separate out. I'd be a little concerned about re-introducing those bubbles into the helm pump using your system. Was there anything in particular you did to prevent that?
2003 160 Dauntless Golden Daze

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Joined: Thu Sep 28, 2017 9:29 pm

Re: SeaStar Hydraulic bleeding

Postby dtmackey » Sun Jul 07, 2019 10:27 pm

Both fittings screw in the same depth into the bottom and I can understand the small bubbles, but since they rise to the top, simply add additional fluid to increase the level in the jug and the bubbles being returned are pushed to the top and bubble free fluid is fed to the helm pump unit.

A power bleeder is the ideal way to go, but with a power purge system approaching $1,000 for the limited time I'd use it, I couldn't justify the cost so this cost me under $25 and worked like a champ.

If the bubbles were a problem, I could have zip tied a loosely fit cloth to the end of the return hose and run it through the top of the jug and plugged the return fitting on the bottom, that way the bubble would work there way out as the fluid passed through the material and dripped down to the bottom.

When I purged, I turned the wheel numerous times until I had bubble free in both lines and opening and closing the bleed valve between port and starboard bleeding.

Last edited by dtmackey on Sun Jul 07, 2019 10:33 pm, edited 1 time in total.

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Re: SeaStar Hydraulic bleeding

Postby MillieTheBoat » Tue Jul 09, 2019 10:54 am

This is an admirable design. You could market this and sell it for $50 and I would buy it. Thanks!