Hydraulic steering

[wookie]

Hi I have a long keel ketch with hydraulic steering to a pedestal wheel, I find it is quite stiff and judders when turning under power, Under sail it is not quite so bad. Someone said the oil may need bleeding. any ideas?
Thanks

[xsboats]

I have a large ketch with hydraulic steering as well . I installed a schrader valve [used on tire tubes] on the reservoir for the hydraulic system. I use a bike pump to keep the tank pressurized at 25 psi. The steering smoothed out for me and by monitoring the pressure with a guage, I can detect leaks in the system.

[Valiente]

Sounds like air in the fluid. As said already, drain it and bleed it and then pour back the fluid, or renew the fluid if old or "off" looking. I use an aircraft landing gear hydraulic fluid called AT-4 as recommended by the hydraulic system manufacturer, Marol, but your mileage, etc.

[jrd22]

I don't know that air in the system would cause it to be "stiff", generally it will feel kind of mushy, or skip a bit when you turn the wheel. You might be having problems with one of the check valves depending on the make and model of pump. I had a Wagner pump blow out on us not too long ago, it blew one of the threaded caps right out the side of the pump (and a LOT of fluid of course). Before it went it had started to feel "stuck" when trying to turn back from hard over.

[wookie]

Thanks all i will drain and replace with new fluid then see if that does the trick