Leaking Hydraulic Steering

JABS · 03 June 2008, 07:13

The pump behind the wheel is leaking a small amount of oil. I think it is coming out of the filler cap, which seems to be vented. It is really annoying because the oil gets on clothes!

Can anyone tell me:

1) Is it possible to overfill? Should there be some 'space' in the reservoir?

2) What is the expected life of the pump?

3) Is it likely that the pump can be overhauled? It feels like a vane pump. If so, is it likely that there is a repair/rebuild kit available?

4) What type of oil is uesd??

Thanks!

jyasaki · 03 June 2008, 19:23

1) The users manual for your helm should have the correct fill level listed.

2) Probably longer than most other parts of the boat, barring corrosion induced failures. Most hydraulic helms are completely rebuildable.

3) Depends on the brand, but I should think so.

4) See #3 and #1 (change "fill level" to "fluid type".)

jky

Hightower · 03 June 2008, 19:57

It's not possible to "overfill" a helm, but it will get messy

I topped mine up over the winter when temps were low, as the weather has got warmer the oil has expanded and weeped out the vent, down the console and all over the floor. There is a recommended fill level with most helms and as mentioned above you should consult your manual. Much more important to keep an above minimum of oil in the resevoir to stop air getting into the system.

Pump life should be long, however if the hydraulics haven't been maintained correctly then failier can be very quick, any contaminated oil will destroy the components in a hydraulic system. So the secret is to use fresh clean oil for top-ups and keep the dirt out. A visual of the pipework on a regular basis is also a good Idea (chaffed hoses, corroded fittings etc).

Yes, pumps can be overhauled, but only if you know what your doing, if not consult someone that does, steering failier at 40kts is a little bit scary

.

Again, for the oil see your manual or look online. But chances are it's an aircraft grade hydraulic oil that most Marine dealers will stock.

What make is the steering?

Hope this helps.

Limey Linda · 03 June 2008, 19:58

Fluid level should be at least 1 inch below the rim of the filler to allow for expansion due to temp. change and use; it warms up fast. Most systems use standard auto. ATF. Rebuild is expensive unless you can do it yourself. Better to buy a new one.

Hightower · 03 June 2008, 20:01

Quote:

Originally Posted by Limey Linda

Fluid level should be at least 1 inch below the rim of the filler to allow for expansion due to temp. change and use; it warms up fast. Most systems use standard auto. ATF. Rebuild is expensive unless you can do it yourself. Better to buy a new one.

But a new one! do you know how much these things are over here? That's why I bought mine in the States

JABS · 03 June 2008, 20:06

Thanks Guys!

I don't have the manual!

When the new engine was fitted, a new ram and pipes were fitted. The oil that came out was pretty dirty. I suspect it was seriously overfilled since there was no problem until the weather got warmer.

ATF or PAS fluid seems reasonable.

I will syphon a bit out and see how it is.

I will also find out the make ad see about a rebuild kit.

Thanks.

Hightower · 03 June 2008, 20:11

Quote:

Originally Posted by JABS

Thanks Guys!

I don't have the manual!

When the new engine was fitted, a new ram and pipes were fitted. The oil that came out was pretty dirty. I suspect it was seriously overfilled since there was no problem until the weather got warmer.

ATF or PAS fluid seems reasonable.

I will syphon a bit out and see how it is.

I will also find out the make ad see about a rebuild kit.

Thanks.

What makes you think you need a rebuild kit?

Don't use ATF or PAS fluid unless it's an emergancy, use the specification recommended by the manufacturer.

JABS · 04 June 2008, 07:07

There is clearly internal leakage around the vanes. There is a dead band of around ten degrees and it is possible to 'migrate' the wheel whilst going straight.

The boat is 100 miles away, so I can't see the make before the weekend!

Thanks

Erin · 04 June 2008, 13:20

A dead band of 10 deg just means you've got air in the system IIRC. Try bleeding the system with some fresh oil. If it's a Baystar or Seastar you can get their instructions on-line I think. My Hy-drive manual says teh oil should be 1/2 inch below the bottom of the fil hole to allow for expansion.

jyasaki · 04 June 2008, 14:53

I think Erin has it right. Doesn't take much air to make things wonky.

The Seastar/Baystar fluid, IIRC, is an aviation grade hydraulic fluid that has been repackaged (and most likely repriced.) As I recall from a similar discussion, there's nothing all that unusual about it other than possibly some anti-corrosion additives.

The Seastar manual (at least, mine does) says ATF is fine for emergencies, but may increase steering effort. From experience, it doesn't change all that much (needing to top it off and not finding any of the correct stuff qualifies as an emergency, no?)

I always have trouble finding anything on the Sea Star website; have a look for yourself, though: ww2.seastarsteering.com

Oops. Sorry, found it. Here're the instructions for purging a Sea Star system .

If it's some other brand, well, then this is all pretty useless...

jky

Richard B · 13 June 2008, 12:08

Quote:

Originally Posted by JABS

ATF or PAS fluid seems reasonable.

No, it's not! Hydraulic fluid is different. If you need a small quantity, I've probably got some of the proper stuff in my garage. However, if the fluid in there is dirty, you probably need to purge it, refill and bleed. If it's red, then someone's probably put ATF in at some point. Supplies and relaible advice can be sourced fromnm the UK distributors Hypro Marine.