Steering oil / noise

[BogMonster]

My Vipermax has got an Ultraflex UP series helm unit on it (or at least thats what it says on the book...)

When you turn it, it makes a distinct noise - like a "stirring" noise - which I really don't remember being there when it was new and I think it's louder than it used to be when I first noticed it a few months ago. You don't notice it when underway but it's quite obvious when the engine is off. You can also feel it slightly through the wheel - its not obvious but its definitely there.

I checked the oil and when taking the bung out of the top of the unit the oil is certainly not right up to the bung level but I'm not sure what the level is - can't really see much - and I'm not sure where the level is supposed to be - the installation instructions that I got with the boat say "2-3 litres of oil for a typical system" but nothing on checking the levels, whether you are supposed to fill it right up or whether it is supposed to have some air in it to allow for expansion. There was a bit of air pressure inside when I opened the filler bung, but this would be because the sun was on the unit so it was quite warm to the touch. However I assume it also means no leaks.

There are no visible leaks anywhere, the steering works fine and with the engine trim set right it is one-finger light and has no hesitation, just seems that it's not exactly like it used to be so I wondered if I should be concerned? I don't have anything to compare it with.

The oil in them seems to be some funny hydraulic stuff according to the book - Shell Tellus 15 or a few equivalents - which I probably can't get here anyway

[BogMonster]

I should add I've seen this thread

How much fluid should there be in the steering?

and it seems the slight lumpiness could be cavitation in the helm unit if the fluid is a bit low - though there is no evidence of any slack in the system or jerkiness/hesitation in operation.

[Dirk Diggler]

I don't think there's anything special about the oil, other than being a non foaming hydraulic. Ultraflex refer to it as "grade 15" which I believe is it's viscosity rating (ISO I'd imagine)

[jyasaki]

Don't know about Ultraflex, but Seastar specs general purpose aviation grade hydraulic fluid. I bought a gallon can for $18, versus a quart of Seastar fluid for $16. The primary difference is the aviation stuff is dyed red for leak detection, where the Seastar stuff is amber.

Most say that any liquid can be used in a pinch, with viscosity affecting steering effort. You want to avoid anything that may cause rust in the system, though. Hydraulic fluid, ATF, etc; it all works.

I try to keep my helm pretty much topped up with oil. Less chance of having to bleed out any air from the lines (which, though not particularly difficult, is sort of a pain in the ass.)

jky

[Erin]

I keep the oil level in my system just covering the gubbins that you can see when you take the bung out. I found that if it's over-filled then as it expands it oozes out the pressure relief and dribbles down the helm unit and console. Never had to top mine up in 3 years so far.

[Ian M]

Originally Posted by Erin

I keep the oil level in my system just covering the gubbins that you can see when you take the bung out. I found that if it's over-filled then as it expands it oozes out the pressure relief and dribbles down the helm unit and console. Never had to top mine up in 3 years so far.

Yep, same here. Quizzed a chap at one of the boat shows re oil level, as I was getting oil oozing out of the screw in cap, particularly when hot. He advised exactly what Erin said, "just cover the gubbins" Biggest problem was getting the stuff out, since then nothing added. No stirring noise yet .............

[jyasaki]

Originally Posted by Ian M

Yep, same here. Quizzed a chap at one of the boat shows re oil level, as I was getting oil oozing out of the screw in cap, particularly when hot. He advised exactly what Erin said, "just cover the gubbins" Biggest problem was getting the stuff out, since then nothing added. No stirring noise yet .............

I find that a large plastic syringe works well for getting oil in both directions in helms and trim units. You can add appropriately sized plastic tubing if you need more reach.

jky

[Chris]

Up to the brim then remove about 5ml using a syringe.

[BogMonster]

I can certainly get red Dexron type ATF easily enough - if that will be OK then I'll probably use that.

Good idea on the syringe!

Thanks