hydraulic steering issue

SteveHall · 18 October 2013, 21:43

I'm having some issues with my hydraulic steering.

It's hard to explain, but it's not lost any fluid that I can tell - the level through the vent seems normal.

Driving along straight for a short while, turn to port and the wheel sometimes turns between 1/4 and a full turn without any movement of the engine, the wheel feel light and detached, eventually the weight returns and the engine moves. This always seems to be turning to port, and a turn to starboard first and then back to port never has this issue.

jyasaki · 19 October 2013, 03:36

Does the motor move smoothly from lock to lock (when it does move)? Or is it a little jerky? Jerky motion usually means air got into the lines.

I'd suspect air in one line, with bleeding as a first course of action (about the cheapest course of action as well.)

Other than that, perhaps a sticky valve in the helm?

jky

SteveHall · 19 October 2013, 07:43

When it finally gets on the move it's as smooth as always.

colcreate · 19 October 2013, 10:35

What make and model helm do you have and how old is it?
There are different designs some more simple than others which may show faults differently.
A thorough bleed according to the manufacturers instructions should improve things for little cost and you will benefit from fresh fluid if the system is a few years old. If it is a 'valve' in the helm it might clear with a bleed. Inspect the whole system for even the slightest weep especially ram end seals and helm shaft seal.
It doesn't take much over a period of time and small amounts of air migrate to the highest point on one or even both sides of the system. Air can be sucked in and replace lost fluid so you might not notice a drop in level at the helm.

If a bleed doesn't solve it and if you are up to it, most manufacturers supply repair/service kits that only require general hand tools to fit although others can be APITA....
Any doubt though then pass it on to someone qualified to fix, it is a safety critical issue.

SteveHall · 19 October 2013, 13:26

It's a sea star system, been on maybe 5 years.

I've been out today and notice it's only turning to port, very slowly and with no pressure that causes the problem.

If a turn is done with normal force it's fine.

Think the bleed will be done before the next trip out

Dhf · 19 October 2013, 14:09

some hyrodrolic steering units just need topping up every few years, with no apparent loss of oil, I recently topped mine up and it got rid of the same problem as you describe, and my level looked ok before filling but took another half cup of hydro oil, all working good now.

Nos4r2 · 19 October 2013, 14:09

Check the seals on the ram-any oil round them?

SteveHall · 19 October 2013, 17:53

Looked over the system and can't see any leaks, or signs of oil. May try a top up.

Hightower · 20 October 2013, 00:35

Just a tip to try after making sure you're topped up with fluid.

Turn hard to Port until the steering wheel stops, then turn it some more. You might need to use a bit of force to do this but all things being equal the safety valve inside the helm should open allowing all the pressure to bleed off which means that all of a sudden it will make a noise and the steering wheel will turn. Do this to Starboard as well, this will help to purge your helm of trapped air and make sure that your safety valves are working correctly.

It may just solve your problem too!

colcreate · 20 October 2013, 09:32

If all else fails and as a last resort before handing over to a qualified repairer, you could try the following on a Seastar helm:
"To remove dirt in check valves. Remove check valve plugs. These are the larger plugs on either side on the rear of the helm. Clean ball seats and balls and reassemble. NOTE: Be prepared to lose a certain amount of oil during this procedure. Have a small can available. Refill & purge the system when check valves have been reassembled."

jyasaki · 20 October 2013, 19:47

Quote:

Originally Posted by Hightower

Just a tip to try after making sure you're topped up with fluid.

Exercising the overpressure valves as Hightower suggested helps.

One other thing that seems to help is to run the wheel to lock in one direction, back off about a half turn, and rapidly work the wheel back and forth about 1/4 to 1/2 turn several times. I usually get a bunch of bubbles coming up to the vent (no idea where from.) Repeat at the other lock, then repeat the whole procedure again.

jky

SteveHall · 28 January 2014, 09:27

I am booked to take the boat out early March so need to get this sorted. Anyone got a manual, I didn't get one with my boat? I want to read over bleeding the system and give this a go before I have to order up a service kit.

biffer · 28 January 2014, 10:09

Spin the wheel lock to lock a few time, pull it into the lock to see if the wheel lets go at all, release it slowly, if it, what can only be called farts, then you need to bleed it, holding on the lock will tell if the seals are funny and the fart is telling you there's air in the system

SteveHall · 28 January 2014, 10:22

Cheers Biff! You should set up a Biff.Net forum with all your knowledge

I turned the helm all the way to port and I got to the lock I turned it some more but it only moved about -5 minutes (on a clock face) and I didn't want to force it anymore as that took quite a bit of force, It didn't make any noise or 'pull back' turned it over to starboard and it seems fine, turned left and right 'frantically' and again it seems fine, but then after it has rested turning to port very slowly or lightly it has this problem.

I have thought back on when it started to do it, and it only started to do it soon after someone opened the vent on the top of the helm unit, so I think its got air into it, or a lack of fluid, but I topped the fluid up to below the thread for the vent.

Should the fluid level change? as I notice mine goes up and down as you turn..

Should the helm have a slight tick when turning, its always had a tick when turning fast, lock to lock - not that noticeable but still there.

Never having worked or owned a hydraulic system before its all new to me...

biffer · 28 January 2014, 10:56

That clicking is air and the level will go up and down so have plenty of cloth at hand, keep turning it lock to lock, you should be able to put quite some pressure on the lock, I would say 50 lbs, then the other way, don't be tempted to over fill because when it come to rest if there's air in the system it will overflow, if you can make up a reservoir to go on the helm filler it will show you the bubbles coming out, once you've done that and bubbles that haven't gone round the system will need to be bled out of the cylinder at the backend

SteveHall · 28 January 2014, 11:13

OK, so its looking like a air problem not a seal problem..

Few Questions?
How much fluid should be in the helm reservoir ?
Don't think I can make an external reservoir as I don't have anything that will match that thread and be water tight - so I will have to keep topping it up.

What is the procedure for bleeding /topping up at the helm? turn from lock to lock and keep topping up the fluid?

What is the procedure for bleeding at the ram?

Should the helm vent / fill thumb screw be air tight?

Without a manual I am lost.

biffer · 28 January 2014, 12:44

Quote:

Originally Posted by SteveHall

OK, so its looking like a air problem not a seal problem.. Few Questions? How much fluid should be in the helm reservoir ? Don't think I can make an external reservoir as I don't have anything that will match that thread and be water tight - so I will have to keep topping it up. What is the procedure for bleeding /topping up at the helm? turn from lock to lock and keep topping up the fluid? What is the procedure for bleeding at the ram? Should the helm vent / fill thumb screw be air tight? Without a manual I am lost.

Thumb screw will have a vent. Not critical on the helm for top up, if you do too much it will come back out when you leave it for a while, ram, you need a bit of pipe and a container, pipe on bleed nipple, hard over on lock, undo one, you will know which one it will have some force, if you're unsure if you have all the air at the ram, link the bleed nipples together with a clear tube, open nipples and turn wheel if you see bubbles keep going with the bleed, I'm sure I've forgotten something, someone will let me or you know

SteveHall · 28 January 2014, 14:46

Got an email from Tom @ JBT

Think I need to find someone with a Power purge system, as they seem impressive!

Anyone know anyone in the NW with one? I have dropped LPB a mail to see if they have one.

jyasaki · 28 January 2014, 15:20

Quote:

Originally Posted by SteveHall

How much fluid should be in the helm reservoir ?

In general, as much as you can get in there without it spilling out (well, you have to be able to get the plug in, but it should be pretty much full.)

Quote:

Don't think I can make an external reservoir as I don't have anything that will match that thread and be water tight - so I will have to keep topping it up.

Are you talking about a permanent external reservoir? Not really sure that's needed.

If you're talking about for bleeding, I made one up, but don't recall the specifics. The plug is a standard pipe thread size, though, as I recall.

Quote:

What is the procedure for bleeding /topping up at the helm? turn from lock to lock and keep topping up the fluid?

What is the procedure for bleeding at the ram?

Procedure for topping up is easy: remove plug, fill, install plug.

Procedure for bleeding is not helm/ram specific, as it's all one system:

Page 15 of this guy shows the procedure for the standard cylinder:
http://www.seastarsolutions.com/wp-c...5/296221-E.pdf

If you have a different cylinder, it will probably be listed here:
SeaStar Solutions

Quote:

Should the helm vent / fill thumb screw be air tight?

Don't think it really matters as long as water and dirt don't get in. The plug has a chintzy little rubber gasket, but it is vented to allow for expansion and contraction of the fluid due to temperature, so no, it's not airtight.

jky