Hynautic Steering - Need Advice

[adt2]

Our flybridge steering unit is leaking like a sieve again. Pools of steering fluid in both forward corners of the flybridge. It just runs right out the center of the shaft.

My mechanic tells me it's not a user-serviceable unit and that if it's leaking that bad I need to disconnect it and send it in to be rebuilt. Previous owner says that's already been done "by the best shop in Florida" and yet it still leaks like a sieve. Guy behind me on the dock says he has a Hynautic system and parts are still available.

This is currently my number one to-do item, so any advice is appreciated.

[Sadey]

You can order the rebuild kit and DIY. Make sure you follow directions step by step. We had our lower helm steering loose fluid. We had it rebuilt at Green Turtle Marina KY while on our way up river, cost was $275 in 2020. Not sure how long we were without steering. Only way we discovered it was by the puddle of fluid on the new bead spread in the vip state, wife was pissed. Luckily it wasn't Freebird's bed, that might have been disastrous!

[jmooney]

I had our upper helm pump leak and I decided to rebuild both pumps and the steering cylinder. I did the pumps myself and had a shop in NC do the cylinder. It wasn’t hard to do the pumps, but they disassembled from the rear . If you don’t do this , you are going to have to force seals on the shaft and this is probably why some rebuilds don’t last long . If you get a rebuild kit look carefully at the o-rings , they are not all alike. Mark the parts so they go back in the same relationship. The kit directions will help . Do not disassemble the pump on the fly bridge, parts will fly everywhere, especially the ball bearings , and they are hard to get . I flushed the entire system when I was finished. Several years now , and no problems.

[Captain Ralph]

The kids before me are correct. It is repairable.

Shopping for another "spare" steering pump may be a good investment also. Reduces the down time between repairs.

Sadly, the original kits and parts are getting old just sitting on somebody's shelf.
Soon to be no more.
The next rebuilds may include lots of seal and O ring measurements and matching.

[adt2]

Okay, good to know they're repairable. Next question...how do I determine which rebuild kit I need? I've got a photo of the numbers stamped into the back of the steering unit if that helps.

[Captain Ralph]

Okay, good to know they're repairable. Next question...how do I determine which rebuild kit I need? I've got a photo of the numbers stamped into the back of the steering unit if that helps.

.
And the number is?? H*** ??

[adt2]

Whoops...sorry. Looks like the number is H42-04.

[Captain Ralph]

WestMArine currently has these on clearance sale.
https://www.westmarine.com/seastar-s...roducts__en_US
Go here for new before shopping for a used one.

Kit pn HS-04

[bostonhatteras]

What pressure do you have in the system? If I pump up to more than 20 psi the upper helm will weep. If I leave it at 10 psi it doesn't. No change in performance either way. Two H-21 units aboard, upper and lower helms. System contains dexron 3 atf btw

[adt2]

Ours uses much higher pressure. 30-40psi