Hydraulic Autopilot Pump

[ohthetrees]

I'm posting on behalf of my 80 year old dad who doesn't really do internet.


He's refitting an old fashioned wooden ketch in Trinidad. He has hydraulic steering and wanted an autopilot. He bought and hired a local to plumb in a a Kobelt Accusteer HRP-35 autopilot pump, which is hooked up to a new B&G autopilot controller. The problem he is having is when the autopilot active it turns the wheel instead of the rudder. If he holds the wheel still, the rudder moves as expected. His system is arranged like the attached diagram, but does NOT have the optional "safety and bypass valve". Does anyone have any insight into what is going on?





I don't really know much about this stuff (my own boat has cable steering).


Thanks for your help in advance!

[dfelsent]

Wild guess. The kobelt installation assumes check valves in the helm pump that the existing one does not have. Or something along those lines.
I’m quite ignorant about hydraulic steering though
I’d Call Kobelt.

[ohthetrees]

Originally Posted by dfelsent

Wild guess. The kobelt installation assumes check valves in the helm pump that the existing one does not have. Or something along those lines.
I’m quite ignorant about hydraulic steering though
I’d Call Kobelt.

Yes, good advice, thanks.

[skipperpete]

dfelsent, it looks like you spotted the problem, I looked up the details of the Kobelt helm pump and it has internal lock valves, so the autopilot pump would work according to the circuit diagram with the Kobelt helm. Its possible to buy an external lock valve and plumb it in and I’m a bit surprised the installer didn’t do this after seeing the helm turning with the autopilot running.

[Chotu]

Exactly.

No matter if there are supposed to be check valves on the components or not, they are either not there or they are not working.

You’ll need an external set or maybe you’ll need to fix/enable them in the helm somehow.

Good on your dad for being 80 and wooden ketch in Trinidad. Wow!

[Toccata]

Hydrive in South Australia (hydrive.com.au) have an auto locking shuttle valve, called a "Dual Lock Valve" that will solve this problem.
Great company to deal with

[pcmm]

I had a similar problem with my Hynautic system on my boat. During my refit, I rebuilt the system and the original bypass/safety valve had to be replaced, what I didn't know at the time was the check valves were in that block and not the helm itself. Compounding that was I was given inccorect advice from seastar. What I ended up with was a hydraulic steering system WITH fed back, When I installed my AP pump I had to purchase an "anti-chatter" valve block to install between the helm and the pump. Solved the problem.

That is likely your next action. I used one of these:

https://www.stevestonmarine.com/tele...ings-and-Parts

[ohthetrees]

Thanks guys , great stuff.

[Sailor 99]

Originally Posted by ohthetrees

Thanks guys , great stuff.

I really don't see what line T is for. Should it be hooked up? Regardless I don't believe you want check valves you want normally open 12 volt solenoid valves that will close when the system is powered up. These should be installed between the helm pump and the pilot pump.

Check valves permit flow only one way and if you put 2 of the on your steering system the wheel will never turn.

I think a call to the manufacturer is in order. None of this stuff is cheap and a phone call is.

[pcmm]

Originally Posted by Sailor 99

I really don't see what line T is for. Should it be hooked up? Regardless I don't believe you want check valves you want normally open 12 volt solenoid valves that will close when the system is powered up. These should be installed between the helm pump and the pilot pump.

Check valves permit flow only one way and if you put 2 of the on your steering system the wheel will never turn.

I think a call to the manufacturer is in order. None of this stuff is cheap and a phone call is.

The T's are where the AP pump connects to the main steering lines. Without that the pump won't pump anything. 12v Solenoids would work too, just don't see it very often. You could probably power the solenoids off the "clutch" function of the AP Normally Hydraulic Helms have check valves built into them for just this reason. Mine and the OP's just doesn't have them built in. Either way would work, just solenoids would be a bit more complex to implement.