Hydraulic steering - change from pressurised reservoir to gravity one

[chrisisbd]

We have a little (10.5 metre) steel boat on the canals in France.  It has hydraulic steering with two wheels, one in the saloon and one out on the flying bridge.

 

As it is at the moment (as it was when we bought it) the fluid reservoir for the steering is down low near the engine so the system has to be pressurised (with a bicycle pump) at the reservoir to ensure that the whole system stays full of fluid.  This is a bit of a nuisance because, firstly it's one more job that needs doing when setting off and secondly the pressure in the system does tend to mean that a little bit of oil creeps past the seals at the wheels.

 

I can see no good reason why I can't move the fluid reservoir up to the flying bridge, just above the wheel and have a gravity fed system.  Can anyone see any good reason why this won't work?  Is there any significant advantage to the existing pressurised system apart from the reservoir being 'downstairs'?

[Alan de Enfield]

I have a similar situation with a helm in the saloon and a helm on the flybridge, unlike yours It does not have a pressurised tank, but each 'wheel' has a tank behind it which supplys the oil to the piston.

 

Illustration - you can fill both 'tanks' from the flybridge filler and bleeding out the air on the piston.

 

If it is of any help I can send the full Vetus manual whuch you can maybe use to adapt your system

 

 

Edited October 4, 2021 by Alan de Enfield

[chrisisbd]

Thanks Alan, that makes a lot of sense to me and suggests that my ideas about 'unpressurising' my system are reasonable.

 

I suspect that my pressurised system may have been created by someone with more ambition than sense in that he had rather inflated ideas about his boat (previous owner).

 

I'll take a longer look at the actual practicalities tomorrow.

 

[Bee]

I think you are right. As far as I know there is no need to pressurise the system, the steering pump - the thing the wheel is attached to - has maybe 5 little cylinders and pistons in it and an angled plate that pushes the pistons in one at a time as you turn the wheel. (In fact it is a smooth continuous action) That is the pressurising bit that pushes fluid to the ram. On my boat the wheel and pump are up in the wheelhouse so higher than the ram and it works entirely by gravity. If the reservoir (basically just the pump body( is full then the whole system should just work without any separate reservoir.  The filler plug on the upper wheel might have a tiny air hole in it, the filler plug on the lower wheel should'nt or you will have a puddle of oil under it.  I would just try it and see.