Hydraulic pump alternatives

[jtdums]

Traced a leak in the hydraulic steering to a crack in the body of my Simrad auto pilot pump. (Looks like PO maybe over tightened line fitting and tried to JB weld housing crack)

Leak is slow, but persistent so looking into replacement.

Do I need to use a replacement Simrad pump?
Simrad
or can I go with an Octopus of similar specs?
Octopus

I'm not trying to be cheap, but frugal on the other hand...

The cylinder range on the Simrad pump is larger, but the liters per minute are the same. Do I just need to identify from my ram the cylinder size and ensure that it falls within the 12-23 cubic inches supplied by the Octopus pump?
Thank you

 

[sean9c]

You can use the Octopus pump. You need to make sure that it does have sufficient output. What they normally look for is can the helm go hard over to hard over in appx 10 seconds. So you need to know the cylinder volume and the pump output and just do the math. The output range on that Simrad pump seems too large, I wouldn't be surprised if its a misprint.

 

[tiltrider1]

I noticed that Simrad pump specs up to 33ci while the octopus specs 23ci. If 23ci is sufficient then you are good to go.

 

[jtdums]

Great. Thank you both. I'm headed back to the boat on Friday so I'll take a good look at the cylinder to verify sufficient volume coming from the pump.

One more question if anyone is willing...
Simrad installation instructions call for hard lines from the helm to the pump (as are currently there already), but the Octopus instructions call for installation with soft high pressure lines to create a vibration "break" to prevent fatigue and noise.

Any consensus on the "best" way?

 

[sunchaser]

I’d be against undersizing the pump without knowing more via a mini study. First the entire system needs to be evaluated. Line diameter, run length, bends, cylinder size etc. Furuno has a great tutorial you can pull up to ensure pump size is adequately calculated and testing done.

 

[sean9c]

Great. Thank you both. I'm headed back to the boat on Friday so I'll take a good look at the cylinder to verify sufficient volume coming from the pump.

One more question if anyone is willing...
Simrad installation instructions call for hard lines from the helm to the pump (as are currently there already), but the Octopus instructions call for installation with soft high pressure lines to create a vibration "break" to prevent fatigue and noise.

Any consensus on the "best" way?

Pumps vibrate, it's always a good idea to a short piece of hose between the pump and your hard line

 

[jtdums]

I'm a little confused now because the cylinder ram is the SeaStar BA135-7ATM which only has a volume of 8.3 Cu In. However, according to SeaStar's sizing chart this is the correct one for the boat size and application.
Where I'm confused is that the existing simrad pump lists its low end at 9.3 Cu In which is clearly larger then the cylinder capacity.
Do you take into account the volume in the lines and helms when initially sizing?