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Seastar leak at fittings

Posted: May 5th, 2023, 9:30 pm
by Helmsman
I sold my Carver and have a trawler now, but thought I would lean on this community’s experts since I received so much great advice from folks her over the years.

I have a Seastar hydraulic steering system. I recently had a yard install an Auto Pilot. The tech had a lot of problems stopping leaks at the fittings. I checked today, and there is still two small leaks at the fittings in the lazarette.

The setup is this. I have 3/8” hydraulic lines coming from the helm. Two of them each attach to a 3/8” tee which the bottom of the tee attaches to the hose going to the ram. The other arm (top of the tee) goes into a 600 WOG valve. All of this was originally from the manufacturer. The other end of the valve is used to attach to the 3/8” Seastar hose to the pump.

The return line from the helm feeds into its own shutoff valve, and then a hose is attached to the pump return.

He also attempted to attach a Furuno SafeHelm2 between the starboard hose and the tee fitting. That leaked, he took it off, re-attached the hose to the tee and it remains uninstalled. He replaced the 600 WOG 3/8” valve with 1000 WOG 3/8” valves.

It is now weeping at the return valve on the pump side. It is also weeping between the starboard tee and the valve.

I have moved the boat to a new yard, and plan to order new fittings and replace the work the tech “completed”. I would like to order the fittings but am not sure what tee I need. I am attaching a picture of the original tee, original 3/8” valve, and 3/8” fitting. Or, alternatively, can I just tighten the offending connections? The sealant is gasoila soft set.

Sorry for the length but hope someone here can help. Any advice would be appreciated.
IMG_4084.jpeg

Re: Seastar leak at fittings

Posted: May 5th, 2023, 9:53 pm
by bud37
I am assuming those are the correct spec for the hoses........ I feel your pain with those fittings. Over the last 15 or so years offshore fitting thread cutting/ rolling has gotten bad. I found I had to go thru a number of fittings ( thread depth/sizing did not match ) before I got a proper seal without having to overtighten. We were taught that proper threads cut on pipe never require pipe dope to seal only lube the threads. Some of the bad brass fittings clearly leaked right where the thread machine stopped, under close inspection a seam can be seen and no amount of tape or dope will stop it if there is any line pressure.

Before you reef em down just remember if you use thread tape that it is possible to split fittings with excess pressure exerted. Have a close look at your fittings with a magnifying glass.

Trawler nice... :down:

Re: Seastar leak at fittings

Posted: May 5th, 2023, 10:56 pm
by Helmsman
bud37 wrote:Source of the post I am assuming those are the correct spec for the hoses

Before you reef em down just remember if you use thread tape that it is possible to split fittings with excess pressure exerted. Have a close look at your fittings with a magnifying glass.

Trawler nice... :down:


Thanks Bud. The 3/8” is the correct spec. The confusing thing to me is that the nipple is described as 3/8” but has a different diameter on each side. I have been unable to find the tee. I expect if I buy the Seastar fittings from one of the marine stores they will have a better shot at working.

Re: Seastar leak at fittings

Posted: May 6th, 2023, 5:39 am
by Midnightsun
Valve side is 3/8" NPT. The other side looks like 3/8" compression but that is just a guess. The WOG terminology is simply Water/Oil/Gas rated. Using a higher number from 600 PSI to 1000 is not a problem. Use a hydraulic thread sealer such as Loctite 545. https://www.henkel-adhesives.com/ca/en/ ... _5450.html

Re: Seastar leak at fittings

Posted: May 6th, 2023, 8:23 am
by Viper
Are you hooking up the Seastar lines with compression fittings to the TEE in the picture? The TEE looks like NPT and if that's where the Seastar compression hardware is hooking up to it's the wrong TEE.

Re: Seastar leak at fittings

Posted: May 6th, 2023, 9:52 am
by bud37
Helmsman wrote:Source of the post Thanks Bud. The 3/8” is the correct spec. The confusing thing to me is that the nipple is described as 3/8” but has a different diameter on each side. I have been unable to find the tee. I expect if I buy the Seastar fittings from one of the marine stores they will have a better shot at working


See what Hans said, one side is NPT the other should be to connect to hose...combo fitting.

Re: Seastar leak at fittings

Posted: May 6th, 2023, 9:56 am
by Helmsman
Viper wrote:Source of the post Are you hooking up the Seastar lines with compression fittings to the TEE in the picture? The TEE looks like NPT and if that's where the Seastar compression hardware is hooking up to it's the wrong TEE.


The two original lines from the factory may not be seastar. The boat is a new boat built in Asia. The two original lines are on the tee on the left, one from the helm, the other to the ram. The new Seastar hose runs from the fitting on the right to the pump. I will post a picture of the connected set up in just a second.

Re: Seastar leak at fittings

Posted: May 6th, 2023, 9:59 am
by Helmsman
Here some pictures

Re: Seastar leak at fittings

Posted: May 6th, 2023, 10:07 am
by bud37
Can you take any of these parts to a hydraulic shop near you......they may have experience with offshore fittings dealing with tractors and equipment hydraulics.......most of these things are standard industry bits from somewhere, problem comes from metric to SAE type threads.....but like I said the NPT threads may just be poorly cut on either the male end or female......good luck man...

Re: Seastar leak at fittings

Posted: May 6th, 2023, 10:18 am
by Helmsman
Ignore the first picture of the three. That was his first attempt with “nonstandard hoses”.I ordered Seastar for the pump and he replaced the nonstandard hoses. The second picture shows the next iteration, and the third shows what is there now. The center line is the return and is leaking on the side the valve handle is covering. The other leak is at the one on the right and is slightly weeping between the tee and the valve.

The original picture in the first post shows the original setup. That particular tee was stripped by the tech and replaced with two fittings because he couldn’t find that tee.

I have a hydraulics guy up lined up to fix it, but would like to have all of the right, high quality fittings he might need to correct it. When you go to look for fittings, the names and types of fittings are called all kinds of different things.