Hydraulic cylinder flow question

[Gregster613]

Re: Hydraulic cylinder disassembly help

Good as new, just waiting for the paint to dry.Hydraulic cylinder disassembly help-img_20190523_110040690-jpg

Hi all, I am trying to paste STx's cylinder repair as a guide to help me properly frame my question. In his picture of the completed repair; as on most cylinders, there are 2 ports. I have an idea but just don't fully understand the proper flow of oil within a cylinder. I am going to install a diverter valve on my machine - within the curl circuit - and am not sure which port on the cylinder controls the curl down or the retract up? I "assume" that the port nearest the gland end "should/might" be the down curl and the port nearest the solid end and farthest away from the gland is the retract? If I am correct thinking this, I'm good to go - but - am I?

When I curl down and am holding my hand on the line, it seems to feel like fluid is pumping through it - but - at the end of the action the line tightens up and both lines feel as if fluid is flowing through them? This is an open circuit and may be the way it's supposed to be, as it is the same sense of feel on the retract line also? I have searched and not found anything pertinent to my question so I am asking for a thought here. I've never had a cylinder apart before and don't really know how the fluid flows within the cylinder. I know it goes in one end and returns out the other but that's it.

I feel like a dufus as I may already be correct in my "assumption" but I don't really know. I don't want to plumb everything up and then have to change lines around afterwards. With my luck the lines would be too short and I'd have to start over again. I'm pretty sure I can plumb the diverter to the curl circuit just by getting the fluid to flow through the diverter and back into the same lines as before, but when I add the lines down to the thumb is where I am getting confused??

Maybe I'm overthinking it. I haven't received my diverter yet, but it's on its way and I'm trying to plan it all out in my head. If I haven't overly confused everyone, I'm just asking "How does the fluid flow within a cylinder?" Sure would appreciate a little help in understanding the concept.
Thanks, Greg

 

[Dave M7040]

Re a double acting cylinder: while oil is flowing into an end of the cylinder under pressure, oil is escaping out the other port, passing through the control valve and returning to the reservoir.
The escaping oil has pressure in it but less than the the end receiving high pressure from the pump.

The upper end of the curl cylinder, the end closest to the tractor, has the port which causes the bucket to dump as the cylinder push rod extends.

The port closest to the bucket causes the bucket to roll back.

You need to imaging a piston connected to the push rod which you see extending and retracting. The oil comes in one port and pushes on one side of the piston. As the piston moves in response to this push, it forces oil out the other port.

Dave M7040

 

[Gregster613]

Thanks for the explanation Dave M7040, that is what I thought was happening but I wasn't exactly sure. Now I know.
Last night I received my diverter package from Ken's Bolt on Hooks and it has precisely clear instructions with the kit - Thanks Ken!! It is a complete and thorough kit, I will have no issues getting it hooked up.
I should/could have waited before asking my question but am glad I didn't because now I am informed of the actual fluid flow through the cylinders. Time to slowly begin playing with the mounting location and measurement of lines.
Thanks to both of you I am confident I will get all assembled just fine. Greg