Hydraulic Steering Ram Oozes A Little, OK?

[CaptainBob]

My hydraulic steering system (with two wheels) has one ram to the rudder. Four very long rods with threads on each end, and some nuts, hold the whole ram together.

The system has no visible header tank so I was keeping it filled to the brim to ensure it wasn't dropping too low. On reflection I think the slight level variation I was originally seeing was down to ambient temperature fluctuations and perhaps a bubble or two somewhere. So last summer when it got really hot, and I didn't open the lid for a few weeks as we were off the boat, the system over-pressured (I postulate) and caused it to start to drip a small amount of oil from one of the compression fittings and from the blank end of the ram.

Compression fitting now nipped up and seems fine, but the ram is a more difficult task.

It literally just oozes a little. Perhaps a drip a week. Easily manageable. But is it essential to fix prior to using the boat? Seems unlikely to suddenly fail catastrophically.

Is it a common problem? Easily fixed? Perhaps it just perhaps needs a new gasket after all.

I'm hesitant to strip it down as I understand (a chap in the yard once said) bleeding a hydraulic system is very difficult - and we have two separate high points, one at each wheel position, with no obvious bleed valve at one of them. And it's no big deal to just add a little oil as required - I check it regularly anyway.

TY

 

[Eyore]

Sudden failure is highly unlikely, however leaking hydraulic seals don't get better by themselves. Personally it would bug me enough to fix it.

 

[NormanS]

I would expect that each wheel (and pump) has its own tank. Often they have a sight glass or dipstick. The cap on the highest tank should have a breather hole in it to allow for expansion and contraction. The upper tank should not be filled to the brim. The cap on the lower tank should not have a breather. It should be full at all times. The flange ends on the ram will have either a gasket, or an "O" ring, but if it leaks one drip / week I would just keep it under observation.
One way of bleeding the system is to open the manual relief valve, and then just keep turning the wheel in one direction. This will chase any air in the pipework to the tank. The ram should have provision for bleeding it at each end. Hope some of that helps.

 

[Hadenough]

You've got a Nauticat I think. Have you looked behind the panel at the poop deck wheel position? I think you will find a small expansion tank just above the aluminium wheel mechanism. This goes to a plastic pipe from where you fill the system. The one I saw was an original factory bodge using an electrical deck fitting as a filler with a 12mm pipe brazed onto the bottom to take the hose. This provides the head and needs to be vented to deal with expansion. Not withstanding that I'd still get the ram seals sorted.

 

[westernman]

A ram which oozes a bit is not a serious problem. I would not worry about taking the boat out, provided I have a bottle of hydraulic fluid to keep it topped up. However, as mentioned above, it is not going to get better on its own, so sooner or later you are going to replace the seals anyway.

 

[Danbury]

A ram which oozes a bit is not a serious problem. I would not worry about taking the boat out, provided I have a bottle of hydraulic fluid to keep it topped up. However, as mentioned above, it is not going to get better on its own, so sooner or later you are going to replace the seals anyway.

Are seals readily available ? I have a similarly slightly moist ram... but there are no markings on it to assist with model identification.

 

[TradewindSailor]

........

I'm hesitant to strip it down as I understand (a chap in the yard once said) bleeding a hydraulic system is very difficult - and we have two separate high points, one at each wheel position, with no obvious bleed valve at one of them. And it's no big deal to just add a little oil as required - I check it regularly anyway.

TY

I've never known a hydraulic system on a boat that is difficult to bleed or maintain. Generally the air works its way up to the highest point which should be the header tank. The rams have bleed nipple so any air can be extracted in seconds with the aid of a spanner.

If your seals are leaking check the condition of the steering rods. If they are corroded or scored they may need replacing or just polishing. A small leak is not a problem ...... and a little bit of oil on the steering rods is good as it protects the rods and the seals.

If you don't have a translucent header tank at the highest point, add one .... get a brake fluid tank from the car breakers and modify it. If you don't have a header tank you risk sucking air into the autopilot motor causing unpredictable problems.

 

[westernman]

Are seals readily available ? I have a similarly slightly moist ram... but there are no markings on it to assist with model identification.

I think they are. I actually had a set of seals which came with the boat. The previous owner was obviously aware the ram was leaking a bit. I don't think there are a huge number of different rams around. A good shop probably will recognise the unit and have the right seals available.