Hynautic steering losing pressure

[Westfield 11]

The air pressure in my steering reservoir is normally set to 30psi, a few days ago I noticed that it was down to 20psi. I pumped it back up to 30psi, but after 48 hours days it was back down to 20psi again. At that point, I checked the steering cylinder for a fluid leak, but it was bone dry. I also checked the steering box at the lower helm and found it to be dry, ditto for the upper helm. There was no lowering of the fluid level in the reservoir and an application of soapy water to the Schrader valve gave indication of a very, very small air leak, so I changed the entire valve and pumped back up to 30psi again. After 24 hours the pressure was down to 25psi. Any comments or suggestions?

[rustybucket]

Schrader valve, o-ring on fluid cap on reservoir would be my first suspect.

Also the square o-ring at one of the helm stations. It is where the steering shaft goes into the steering box. I had a leak on one once where fluid was running down a wire into a corner away from where you would think it would be leaking. Also, it took very little fluid loss to drop the pressure.

At HVAC shops they sell leak detector, it looks just like dawn in a spray bottle but it works WAAAY better than soapy water at finding a leak. I keep a bottle on the boat and it has come in very handy in the past finding little leaks.

[Pascal]

I agree. Sounds like valve or the cap on the reservoir. Anywhere else would leak fluid

[racclarkson@gmail.com]

I can drop 5-8 PSI from temp in winter.

[Westfield 11]

Thanks, I pumped her up and am traveling again. A gentleman with a sistership has had the same issue for several years and has spent a lot of time and money looking for a leak. It does seem to be an air leak though as opposed to fluid. I’ll be monitoring it closely and plan on ordering a reservoir O-ring and will try that.

[rustybucket]

One mod I did that may help others, I purchased an air hose extension kit and ran the air fill line to midship. This makes it WAAAAYYY easier to pressurize the system than crawling in the hole between the generator and electrical panel to pressurize it.

I also have a M12 air pump that goes to my milwaukee m12 battery drill set.

[Westfield 11]

My compressor is in the same engineroom as the reservoir. But the air space in the reservoir is so small that just touching the nozzle to the valve pegs the gauge! I’m going to a bicycle shop and getting a mini hand pump for the job.
I did learn the once the system had run for 7 hours, 30psi had become almost 40pst and the level rose 1/4”.

[rsmith]

The reservoir should be half full of fluid. If it’s more the volume of air capacity is reduced geometrically as the volume is reduced. If you have a leak the pressure drops quicker the less volume of air in the reservoir can

[divert00]

I had simliar mysterious leak down on one of my Hynautic engine controls. After checking the
aforementioned suspects, it turned out to be the gauge, which is impossible to use leak detect on.

BTW, when I was stumped, I finally called Hyanutic (SeaStar) tech support and they immediately
identified the gauge as the culprit.

John McCarley
Water Colors
'86 63MY
Wrightsville Beach NC

[Westfield 11]

I had simliar mysterious leak down on one of my Hynautic engine controls. After checking the
aforementioned suspects, it turned out to be the gauge, which is impossible to use leak detect on.

BTW, when I was stumped, I finally called Hyanutic (SeaStar) tech support and they immediately
identified the gauge as the culprit.

John McCarley
Water Colors
'86 63MY
Wrightsville Beach NC

That is very helpful. I had not considered the gauge at all as a possible leak source. If a cap o-ring does not fix it I’ll try replacing the gauge.