Hydrauic boat steering has air entering, How?
Hydrauic boat steering has air entering, How?
(OP)
I have a friend in Sweden with who I communicate via Skype. He describes his boat hydraulic steering using copper pipes and some rubber hoses. Operations are jerky, with no movement of the steering cylinder followed by a jerk. Seems like air on the pressure side then. He maybe gets one drop of oil leak a week, yet apparently on the suction side of his steering wheel "pump", in one direction, could he be sucking in air? Is there the possibility that the viscosity or molecule size of the oil is such that it does not leak out much oil under pressure, but air can get in, under the suction condition?
Rudder is not stuck and moves freely when not h hooked to the steering cylinder.
The tests he has done certainly appear to show air in the system. Bleeding has not been done, but lowering the steering piston seems to solve his problem (letting air get to a reservoir).
I suggested locking the steering cylinder and seeing if he can expel anything via the pressure lines, looking for a leak.
thoughts or suggestions?
Rudder is not stuck and moves freely when not h hooked to the steering cylinder.
The tests he has done certainly appear to show air in the system. Bleeding has not been done, but lowering the steering piston seems to solve his problem (letting air get to a reservoir).
I suggested locking the steering cylinder and seeing if he can expel anything via the pressure lines, looking for a leak.
thoughts or suggestions?





RE: Hydrauic boat steering has air entering, How?
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Hydrauic boat steering has air entering, How?
Check for drop in oil level. Turbulence at impeller with low oil volume can introduce bubbles in the oil.
Assume the cylinder is dual acting...in that case, could be pulling small amount of air past the seal.
Impeller could be wearing out as well.
I would also bleed the system.
RE: Hydrauic boat steering has air entering, How?
Hey Ron: sounds like you are a pretty well rounded engineer. I'd bet you have a ham license as well. I'm one, as does Svenska friend.
RE: Hydrauic boat steering has air entering, How?
Pretty much grew up in a junkyard! Lots of varied experience there.
RE: Hydrauic boat steering has air entering, How?
RE: Hydrauic boat steering has air entering, How?
Back in the late 70's we were constantly underfunded in our geotech lab. Corporate office wouldn't let us buy a sample extruder (for shelby tubes). Went to junkyard and bought a hydraulic tailgate for a pickup truck for less that $100. Stripped it and built a foot-operated hydraulic sample extruder. Visited the lab a couple of years ago and they were still using it.
RE: Hydrauic boat steering has air entering, How?
If the shafts penetrate the front and back plate I would also check them out.
RE: Hydrauic boat steering has air entering, How?
RE: Hydrauic boat steering has air entering, How?
RE: Hydrauic boat steering has air entering, How?