Help with dropping cylinder

[Topgunramen]

Hello all,
I saw the forum when I was looking for some help on an ongoing issue I'm having with a set of cylinders on a linen extractor press basket at a commercial laundry.

Ignore the valve set and cylinder on the left in the schematic, everything im talking about should be on the right. The basket has intermittent problems going up and down at a snail pace that will go away when you reverse and then go ahead. Also, it always gets to the top of its movement and immediately starts to drop about a centimeter or so in 10 seconds. I don't work very often with hydraulics so this is all very new to me. Both cylinders have been replaced to no avail as well as the uppermost valve (at the bottom of the print.) What here would be most to least likely to cause this kind of issue?


View attachment 20241215_124614.jpg

 

[BEMPE16524]

have you considered counterbalance valve for both cylinders?
how big is the cylinders?
not sure if you have bled the air during new installation?

 

[MintJulep]

everything im talking about should be on the right.

It's not.

Post the entire schematic please.

 

[Topgunramen]

have you considered counterbalance valve for both cylinders?
how big is the cylinders?
not sure if you have bled the air during new installation?

Are 5.3 and 5.4 counterbalance valves? It looks like they only service the extend stroke. They're about 6 ft long extended with a 5 inch barrel. They've been bled by the book more than once.

 

[Topgunramen]

It's not.

Post the entire schematic please.

View attachment 20241216_144527.jpg

 

[EdStainless]

When they were re-bled was there any air?
If so then I suspect a leak, perhaps only under suction.

 

[BEMPE16524]

small leak is common for stackup configuration like this.
it could be due to the port o-ring that already worn out (become flat).
are you using Wanfluh valves? some of the part number seems like theirs.
Not sure why the system uses one direction c/balance only, because if you use one-directional counterbalance valves (as appears here), you may only achieve load holding/control in one direction (e.g., when lowering the basket), while upward movement might lack the same control.