Loss of hydraulic steering

[Sandibar]

We had a failure of hydraulic steering a couple of weeks ago approaching Christiansoe islands in the southern baltic in 20 kts of wind and (for us) rather big waves. Wife was steering while I was taking down the main to get in the harbour. Boat would not turn easily into the wind, probably because of too low engine revs and wife turned wheel hard, when something popped and there was no response from the rudder.
I have an emergency tiller that was out in seconds, but had never tried it before. Trying to disengage the ram and screw the short tiller on top of rudder post was a bit stressful, but did manage in the end and we got into harbour without more drama.
When I tracked the problem, I noticed that one of the hoses from the steering pump to the ram had burst. I'm pretty sure this should not happen, so am a bit worried for the system. The boat has two steering stations + a recently installed hydraulic autopilot pump. There were some problems earlier after the AP installation with oil leaking from a vent in the outside pump, but everything was fixed and working by the time this happened.

Basic question: can you burst a high pressure hydraulic hose with a steering pump at all or do I have some kind of underlying problem at hand?

Things that come to mind:
- too much oil in the steering pump --> excessive pressure in the system
- mixed two types of oil in the system --> not compatible with each other

Incidentally we lost steering a second time and in a worse spot: tight marina with fresh wind. This time it was the reused fitting of the fixed hose that gave, which is no mystery. With the earlier experience the emergency tiller was on in a flash this time . Will redo the fittings now that we're back in Finland.

[deblen]

Originally Posted by Sandibar

We had a failure of hydraulic steering a couple of weeks ago approaching Christiansoe islands in the southern baltic in 20 kts of wind and (for us) rather big waves. Wife was steering while I was taking down the main to get in the harbour. Boat would not turn easily into the wind, probably because of too low engine revs and wife turned wheel hard, when something popped and there was no response from the rudder.
I have an emergency tiller that was out in seconds, but had never tried it before. Trying to disengage the ram and screw the short tiller on top of rudder post was a bit stressful, but did manage in the end and we got into harbour without more drama.
When I tracked the problem, I noticed that one of the hoses from the steering pump to the ram had burst. I'm pretty sure this should not happen, so am a bit worried for the system. The boat has two steering stations + a recently installed hydraulic autopilot pump. There were some problems earlier after the AP installation with oil leaking from a vent in the outside pump, but everything was fixed and working by the time this happened.

Basic question: can you burst a high pressure hydraulic hose with a steering pump at all or do I have some kind of underlying problem at hand?

Things that come to mind:
- too much oil in the steering pump --> excessive pressure in the system
- mixed two types of oil in the system --> not compatible with each other

Incidentally we lost steering a second time and in a worse spot: tight marina with fresh wind. This time it was the reused fitting of the fixed hose that gave, which is no mystery. With the earlier experience the emergency tiller was on in a flash this time . Will redo the fittings now that we're back in Finland.

The hose don't usually burst. It's usually a crimp or other joint.

But they seem to be supplying cheap looking hose these days.
Was there signs of hose chafing at the break point.

Years ago,copper refrigeration tubing was used.
Regular 3000PSI hydraulic hose & fittings was also common & reliable.

An autopilot pump can create pressures up to 1000 PSI if hard over.
Quite a bit more than the manual hand steering pump creates.

I would suggest you replace the cheap hose,if that is what was used,with 2 lengths of regular 3000PSI hydraulic hose,from helm to cyl. or to the Autopilot tees & then to cyl.
Use regular high pressure hyd. fittings also. No hose clamps or push inserts etc.

You can use either regular hyd. fluid or Auto trans fluid in most systems younger than 30yrs but check your manual. ATF has detergents,etc. in it.
I prefer plain hydraulic oil.

Hope this helps/ Len

[Sandibar]

THanks Len,

the tubing burst in the middle, no chafe involved. Not sure of the quality, but it's pretty thick walled semi-flexible tubing that feels like nylon. I assume that the AP pump has created some high pressure and weakened the (already quite old tubing). Will replace the tube runs and fittings as well this winter. I have both ATF (original installation) as well as plain hydraulic oil in the system, since fixing the autopilot problems. I know this is not ideal and may have caused part of the problems, but ATF was not available on during our cruise this summer and did not want to drain the whole system.

markus

[darylat8750]

If it burst in the middle of a hose with no chafe it must be the wrong hose. Are the failed components things that were used as part of the auto pilot pump installation? If so I would replace every piece of hose and every fitting that was used by that installer with quality hydraulic components. (A good source would be any shop/store that supplies hyd components to the construction industry.) If the hoses/ fittings used in the autopilot install used substandard components I would have a financial discussion with the people that used that junk in a safety related system on my boat. If it wasn't one of the recently changed components I would replace all the hoses in the system. Hoses do age.

[Sandibar]

The burst hose is one of the original ones, from outside steering pump to ram - most likely already 28yrs old. I did the AP installation myself, so its easy to find the guilty party for any problems there

[Lepke]

Get your replacement hoses at a commercial hydraulic or farm supply. I've used many hydraulic systems in commercial applications. A hose will often last 20 or more years in a protected area. Usually on deck hoses will have fitting failures when used with non-stainless ends. Yacht hydraulics appear to me as being light duty. There are hand pumps that produce as much pressure as powered pumps. Hydraulic hoses should be inspected like any other maintenance item, at least yearly.

[boatpoker]

What brand are the helm pumps and ram ?

I just went through six weeks of hell with my hydraulics that started with a broken hose and ended with the difficulty of obtaining proprietary fittings. I eventually ripped out everything and installed new after I got tired of trying to patch up a poorly spec'd and even more poorly installed system.

[deblen]

Originally Posted by Lepke

Get your replacement hoses at a commercial hydraulic or farm supply. I've used many hydraulic systems in commercial applications. A hose will often last 20 or more years in a protected area. Usually on deck hoses will have fitting failures when used with non-stainless ends. Yacht hydraulics appear to me as being light duty. There are hand pumps that produce as much pressure as powered pumps. Hydraulic hoses should be inspected like any other maintenance item, at least yearly.

Agree!

[deblen]

Originally Posted by boatpoker

What brand are the helm pumps and ram ?

I just went through six weeks of hell with my hydraulics that started with a broken hose and ended with the difficulty of obtaining proprietary fittings. I eventually ripped out everything and installed new after I got tired of trying to patch up a poorly spec'd and even more poorly installed system.

Brings back bad memories.
When hoses start to burst,it's best to replace with new from a hydraulic shop. Have them make up the hoses & crimps in lengths required.
Start right at the ram & helm for compatibility.Less expensive in the long run IMHO.
Most "holes" in the ram & helm will be ORB or NPT for N.American built stuff.

No idea what the UK/EU use,but I would purchase some spare fittings for future.

Cheers/ Len

[boatnerd]

You might try cutting the hose at the failure point to inspect the reinforcement braid. Are there signs of rust from the steel braid deteriorating? Ive seen cheap hydraulic hoses on a few European boats( fairline, sunrunners) where seawater has entered the steel reinforcement. One hose ive seen fail had nylon zipties cut through rubber cover ever so slightly that allow water to enter. .

[Sandibar]

Thanks for all the feedback! The pumps are Vetus and I assume the ram also. The burst tube has no reinforcement, it's plain plastic with 2mm wall thickness. Will replace the hoses this winter. Can't use shop-crimped connectors without making larger holes in the boat, which I'd rather not.

The 8mm hose/fittings used in the original installation is getting rare apparently, at least getting suitable parts for the AP installation was impossible, so went with 10mm and will do the replacements also in 10mm.

[Fuss]

Originally Posted by Sandibar

Thanks for all the feedback! The pumps are Vetus and I assume the ram also. The burst tube has no reinforcement, it's plain plastic with 2mm wall thickness. Will replace the hoses this winter. Can't use shop-crimped connectors without making larger holes in the boat, which I'd rather not.

The 8mm hose/fittings used in the original installation is getting rare apparently, at least getting suitable parts for the AP installation was impossible, so went with 10mm and will do the replacements also in 10mm.

Whats that for a hose, can we see a picture...this is not a hose carrying pressure to the ram??? else it would not last 5 mins.
I have a vetus system...the green larger one. I have never been able to overload it so far..
If you go hard over and keep turning then it goes somehow a bit tighter but does not damage anything.
assuming you have something similar to mine...If you overfill the reservoir then it simply leaks out...from memory, fill so the level is at the bottom of the small 5cm dip stick, not half way up. This dipstick is just to ensure you have enough oil and should not be filled to the top of the stick.

I always try to use the genuine vetus oil.

about the hose...i would ask a hydraulics guy as they will know immediately..... you need to know the problem so you don't get a repeat and instead peace of mind.

[Bill O]

[QUOTE=Sandibar;2183749 The burst tube has no reinforcement, it's plain plastic with 2mm wall thickness. Will replace the hoses this winter. Can't use shop-crimped connectors without making larger holes in the boat, which I'd rather not.

The 8mm hose/fittings used in the original installation is getting rare apparently, at least getting suitable parts for the AP installation was impossible, so went with 10mm and will do the replacements also in 10mm.[/QUOTE]

Doesn't sound like this was an appropriate hose was used for a hydraulic system. If you can't get a shop crimped reinforced hose back in the spot, then as suggested previously use copper line and install either a flare or swage type fittings after you feed the line through. Obviously use copper for the static/non movement lines. From the ram and AP pump you will want to use rubber reinforced hoses to handle the movement and reduce vibration into system from the AP pump.

Copper line will last a very long time.

Bill O.


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