Help me understand power steering???

[Indy1830SS]

I've been working off an on with my power steering (Chaparral 1830SS 4.3LX) and have gotten some helpful comments from a few of you already, but haven't isolated the problem yet. I lack understanding of a few key pieces of the system - maybe some of you mechanical gurus can help.

Let's start with the control valve. I understand what is happening outside - the steering cable pushes or pulls on the valve and it extends the rod as well as actuates the power assist cylinder. When I observe it operating while someone else turns the wheel, I assume that it works like a cylinder control block. Push it and oil flows one way, pull it and oil goes another....but that wouldn't explain how it still works manually and extends the rod on the actuator. I assume the the rod and steering cable are directly connected internally, using the helm's leverage alone w/o power assist. Maybe someone can clarify this operation?

Maybe the real question I have is, should the coupling of the cable to the actuator move or be rigid? When you turn the wheel you can see the port into the actuator move before the cylinder does. Is this a normal slop in the operation and part of it's function? If not normal, maybe that explains the whole mess as well as why there seems to be so much play in the wheel.

For the record, I believe the pump is working. I can hear it change tones when you turn the wheel.

 

[rodbolt]

Re: Help me understand power steering???

the cable must be free to move. it is mechanically tied to the outdrive tiller. it will move the tiller regaurdless of fluid pressure. there is a small amount of port/stbd motion as the cable moves the actuator. once the actuator is moved enough to uncover the valving hydrualic pressure takes over and nulls the input of the cable.
the power assist will move the tiller in the direction of cable motion until it it catches the cable or hits the stop.
we had a local builder that loved to tie the steering cable tight to the hull/transom and created all kinds of issues.]
only took us 2 years and a lot of his money to convince him the last 2 foot or so of cable MUST be free to move.

 

[Indy1830SS]

Re: Help me understand power steering???

So, you are saying that the external movement in and out (port/strbd) at the actuator is normal?

 

[rodbolt]

Re: Help me understand power steering???

yes, its how the spool valve works. no motion no valving thus no steering or erratic steering.

 

[Indy1830SS]

Re: Help me understand power steering???

OK - thanks for clarifying. That makes sense now.