DIY hydraulic steering hose fitting replacement

[mcarthur]

Has anyone done any DIY replacement on their own steering hydraulics?

There was some sea water in the stern area before we bought the boat and the hydraulic hose attachments to the piston have rusted a lot.
Before going too much further I'd like to replace the fittings.

Because there's a lot of hose available, one option is to DIY - cutting off the existing fittings to the piston, and replace with in-field fittings.
There's apparently no reliable local mobile service to come to the boat, and taking off the hoses will be hard (not least because it's about 6m and through a bulkhead to the T-joiner that leads a further 4-5m to the flybridge/cabin steering positions).
From the manufacturer of the piston (L&S) the line is 50 bar pressure and their manual allows screw and crimped hoses to attach to the 1/4 BSPP on the piston.
The current hose OD is 14mm and connector nut being 19mm OD.

I've done a little YT so I can talk some of the talk, but no practical experience. Given the lack of a mobile service, seems like a good time to get the experience I may also need when cruising!
So...has anyone done their own replacement before?

 

[KnotYet]

I have made my own hydraulic assemblies using off the shelf components and hand tools.
In the U.S. I can mail order them from various suppliers. Hopefully that is the case there, too.
It's pretty easy with a little practice.

 

[Bmarler]

My experience is that for screw fittings, you must have the right hose. Did L&S supply the hose for your system?

 

[tiltrider1]

We are talking high pressure hoses here. The simplest answer will be to remove the hose and take it to a hydraulic shop to have a matching replacement made.

 

[KnotYet]

We are talking high pressure hoses here. The simplest answer will be to remove the hose and take it to a hydraulic shop to have a matching replacement made.

Speaking from experience, 50 bar or about 750 psi, is a modest pressure in hydraulics.
The self-assembled hoses, if done properly, will handle many times that pressure.
Beyond convenience, the ability to make your own hose assemblies makes you self-sufficient.
It's like carrying a length of fuel or water hose in case you need it in a place far from home.

 

[dannc]

Tractor and heavy equipment dealers and service companies should also be able to provide hoses and fittings. They should also be able to make the hoses if needed. My itty bitty 40 HP tractor has 2,000 PSI hydraulics with quick connect/disconnect fittings.

 

[luna]

The OP appears to want to cut off the existing rusted fitting and while leaving what could be a 20’ hose in place, install a new field assembled fitting.

Provided that the existing hose is in good shape, that you can cut it without filling the hose with cuttings that will be near impossible to remove and that the hose is designed to accept field assembled fittings, you might, if you are careful, be Ok. It would be handy to have a vise, a vacuum and whatever other tools are required.

To determine if this is possible, your questions need to be answered by the hose and fitting manufacturer.
Any idea who that is?

 

[Frosty]

I'm not sure which type of hose you are talking about, so this may not apply. But my system has the typical Seastar/Seastar Pro hose. I think this is 5/16" hose. They of course tell you to never do your own fittings. In this system the minimum component (the Seastar hose) is rated at 1,000 psi.

However, I did some research and found the Parker field-installable fittings, did some reading and watched some videos, and was pretty sure I would try it. The videos gave me some confidence because it was not just Joe Backyard doing them but actual hydraulic shops and/or people who obviously had a lot of hydraulic equipment to service (farms, etc.)

My resolve was firmed up when I bought a NOS Hynautic kit. I only needed one part of it (ram), but it came with a huge coil of hose and..... Parker field-installable fittings. So apparently back then they thought it was fine and dandy.

I installed the hoses with those fittings and so far they have been 100% fine (about 150 hours of run time). It was not difficult and required no special tools beyond the typical wrenches you would already have. I used SAE20 as hose lube but I'm sure there are many other options.

************

What got me started on this was I had some official Seastar bulkhead hose fitting hoses. When I changed rams they needed to be a bit shorter, but the official line was to buy complete new ones.

BTW, since the field-installable fittings are re-usable, you can use them to practice on a hose offcut if desired (I did).

I got two different types: One is for typical Seastar fittings; and the other for SAE 45º flare (Hynautic).

I could go into more detail, but I'm not sure if we are talking about the same type of hose.

 

[Frosty]

PS: I wanted to add that in my case I wanted to add the fittings "in place" rather than use a vise. Same reason as you in that they were already attached and bedded into the boat.

I did my first practice run in a vise like they showed. Then I did a practice one just by hand. Seemed perfectly doable for one or two fittings (obviously if doing them all day long then no). So then you are just using two spanners.

 

[mcarthur]

Thanks everyone!

The fittings on the cylinder are 1/4 male BSPP and the hose is 3/8 (ID of course for hose). As people pointed out, the pressure is lowish though I'm not taking that lightly.
Taking out the hose to a shop would be a pain as it goes through a bulkhead. It's certainly possible, but I did want to see about in-situ first.

Great to hear your experience @Frosty, exactly what I was hoping for.

Good question about the hose - no idea if it is OEM or bought later. I've looked at the OEM for the cylinder (linked in the original mesg) and it talks about installation of both screw and crimped fittings and shows both. But I've no idea if this hose came with the kit.

While I can cut the existing hose and rusted fittings off with a grinder, I am concerned about residue in the hose which would potentially still have a little oil in it, even after cleaning (as @luna mentioned). But grinder does seem to be the in-field way of doing it - any suggestions?

 

[Frosty]

While I can cut the existing hose and rusted fittings off with a grinder, I am concerned about residue in the hose which would potentially still have a little oil in it, even after cleaning. But grinder does seem to be the in-field way of doing it - any suggestions?

I wouldn't be surprised if the Seastar/similar hose is just weak (and maybe yours is not), but I cut it super easily with one of the plumbing cutters that looks like this (tho not this exact one, as it's something I had bought years ago). It made a nice, square cut and - at least with my hose - there were no "shavings" or anything like that to get into the system.

Amazon.com

 

[luna]

When you work on a boat, you have to be creative. I have a nice Irwin 3" bench vice mounted on a piece of 1/4" aluminum plate so I can clamp it or bolt it to numerous locations on the boat. Working alone, sometimes you really need that 3rd hand.

L & S describes 3 different methods to install 3 different fitting designs on 3 different hose types, Clamp, Screw and Crimp. Only the Screw type would seem to require a vice to install the fitting.

The fittings work with the particular hose. To use Company A's hose with Company B's fittings is a crap shoot.

I would not use a cut off wheel as they are a nightmare to clean up after. The particles are just too small and they get flung everywhere.

To keep the inside of the hose clean before you cut it with your hacksaw while the vice holds the hose, you should be able to do this kind of thing.

Get a few 7/16" test tube brushes like these. Test Tube Brush - Fan Tip
Cut off all of the twisted wire handle leaving only about 3/8" of the length left. Any shorter and they usually start coming apart. If that happens toss it, try 1/2" on the next one. Keep the twist tight while cutting.

Working through the open end of the rusted fitting, push into the hose the fuzzy part first with the twisted shank ending right where you want to cut the hose.

Cut the hose and vacuum what you can out while keeping the open end of the hose hanging down. Then twist out your fuzzy plug using needle nose pliers. Do a trial run on a piece of similar hose first, to reveal the bugs.

Run a clean brush through the hose a few times and you should be good.

 

[mcarthur]

Awesome idea @luna thank you!
I will find out the hose manufacturer next time I can get to the boat. I had (wrongly) thought that it was the hose size (ID and OD) that mattered for that end of the fittings, not realising the manufacturer was important (presumably because of small differences in ID/OD sizing?)

Thanks @Frosty - I didn't even think of that type of cutter. I'll look more closely at the hose next time I'm there, but there's very little difference between our 3/8 ID vs your 5/16.
I do have some knipex ratchetting cable cutters (these) - which may work?

 

[Frosty]

I didn't even think of that type of cutter. I'll look more closely at the hose next time I'm there, but there's very little difference between our 3/8 ID vs your 5/16.
I do have some knipex ratchetting cable cutters (these) - which may work?

Those look interesting. It's hard for me to see exactly what the blade looks like. i.e. is it thin, like what I showed, or is it thicker, like a side-cutter would be. Seems like thinner would be good (and maybe it is and I just can't see it).

I did see people use saws for cutting the hose in videos, but I'd be freaking out about dust and dirt in the system. I think with a lot of those they are making up a shorter section so they can blow it out.

When I was watching videos to decide whether to use these (and how to do it), I noticed that many of the hoses were larger than my little 5/16". Plenty of 3/8" and even larger.

Basically you lube the outside of the hose, then twist the first piece *left-handed* onto the hose, almost all the way until it bottoms out, but not quite (you leave a little gap for expansion). It has sharp/coarse threads that bite into the hose.

Then you thread the next piece - which has a long "snout" into that one (the regular right turning way). This second piece will have (on the other end) whatever type of fitting you have to mate up to. In my case I had Seastar's thread (which seems to be a bit unusual) and I also had some SAE 45 flare (Hynautic). But there are others (JIC 37, etc.) I watched a few other videos to figure out the various fitting types so I knew what I had.

After all that it took about 10 minutes to put a fitting on. Almost anti-climactic. I felt comfortable enough by that point to remove one and trim the hose another few inches to make it fit the setup a little better.

 

[KnotYet]

Awesome idea @luna thank you!
I will find out the hose manufacturer next time I can get to the boat. I had (wrongly) thought that it was the hose size (ID and OD) that mattered for that end of the fittings, not realising the manufacturer was important (presumably because of small differences in ID/OD sizing?)

Thanks @Frosty - I didn't even think of that type of cutter. I'll look more closely at the hose next time I'm there, but there's very little difference between our 3/8 ID vs your 5/16.
I do have some knipex ratchetting cable cutters (these) - which may work?

Almost any hand shear that can cut thin sheet metal will cut hose, as will steel cable cutters.

 

[Frosty]

I just got to thinking about something, and then double-checked. That is that this hose must (also?) go by OD, because these field-installable (aka "re-usable) fittings have to thread onto the outside of the hose. But then if you think about it, so do the crimped fitting "cuffs."

Went and looked and while it looks to me like our hose goes by ID, it also looks like there are various standards that mean the OD must be a corresponding size. For reasons mentioned above. These may be marked on the outside of the hose, so not saying it will be a big mystery, but just something to check.

In my case I had a head start because the Hynautic kit I bought (tho I didn't use their hose or most of the rest of the kit) had two of the field installable fittings included. I had some scraps of Seastar hose and they fit that OD fine as well. I then also bought a single new one (because I misplaced one for awhile), plus a couple of the same fittings but with Seastar threaded terminal ends (I was thinking I might thread some Seastar threaded nipples into the Hynautic ram but decided to stick with their SAE 45 instead).

But anyway, still something to check with your hose if you decide to buy some of these fittings. That first "left-handed" cuff has to be able to thread onto the OD of the hose (which you lube first).

PS: I wanted to add one thing. There is a process called "skiving," where you remove a controlled amount of the OD of the hose before installing a fitting. But I don't believe this is something to employ on hydraulic hose. Mind you, I'm a rank amateur. But I think this is for hoses with wire reinforcement where you want the fitting to engage with those wires, not just the rubber/plastic. Of course our hoses don't have wire reinforcement. Also, I did note on several professional videos about the field-installable fittings I had (Parker) that they were meant to fit the OD as-is, not be skived. BTW, I would share part numbers but it sounds like you have different hose and possibly different fittings it needs to thread onto.

That said, if any pros find anything wrong in what I've written, believe them. I only did a deep dive for a couple weeks to figure out whether to use the fittings and how.

 

[luna]

This is why it is important to use the companies hose that is meant to have that company's field assembled, or reusable fittings, it's a system. No skiving required.

I'm not familiar with any hose that you L.H. thread a socket onto the hose and then install the nipple, where the hose does not have an outer jacket of some kind of rubber and at least one layer of a wire mesh. My go to for most things boat is Aeroquip's FC234.

It cuts nicely with a hacksaw as the wire mesh is too tough for your bladed cutter.

 

[Frosty]

This is why it is important to use the companies hose that is meant to have that company's field assembled, or reusable fittings, it's a system. No skiving required.

I just mentioned the skiving so the OP would know that's not something that (from what I can tell) should be done to our type of hose. So he should not count on that to make it fit.

I'm not familiar with any hose that you L.H. thread a socket onto the hose and then install the nipple, where the hose does not have an outer jacket of some kind of rubber and at least one layer of a wire mesh.

This is how the Parker field-installable fittings go on. This type of fitting was included with the Hynautic kit's hose (not sure what brand that hose was), and also comes in a size that works with Seastar hose (which is basically the same size). Neither of those hoses have wire mesh. I suspect only the terminal end fitting is different, because Seastar uses a different threading than most.

It cuts nicely with a hacksaw as the wire mesh is too tough for your bladed cutter.

Does your hydraulic steering hose have wire mesh? The spiral type like wet exhaust hose? If so, it's much more heavy duty than the Seastar/Hynautic hose (but then that's only rated to -- at least for the Seastar -- 1,000psi for regular and 1,500psi for "pro hose).

Here is a video to clarify what I used. You can see that first "cuff" goes on with a left-handed thread.

Basic concept in a 1:27 minute video:

Actual hose being done at a hydraulic shop in a 2:45 video. I found this video to be very good. They are using a larger (but same type of) fitting on what looks like it may be a wire-reinforced hose. I like the old-school lube can.

He mentions his particular hose meeting XYZ standard. As I said, I had that part easy as I started with a couple fittings that came together with a coil of hose to guide me. But I think it's marked on the outside of the hose also.

This one is about 12 minutes long:

 

[Frosty]

One more video I found useful was this one, which simply shows and describes the various styles of fittings. I have two of the ones shown in the video in my steering system: O-ring boss/ORB on some of the Seastar fixed pieces (helm, AP pump) and the SAE 45 on the Hynautic ram hoses.

(Seastar also uses some 3/8" compression fittings with 9/16-24 threads, which I gather are a bit atypical; but in Australia I don't suppose you have Seastar.)