Is this normal?

[TractorLegend]

I have a new grapple with dual 'lids'. Each lid has a single hydraulic ram which hooks up to a typical added on valve block to control them via the joystick.
My question is this: Is it normal for one lid to bleed off- that is- after the tractor is parked several hours the left lid is closed more than the right when they were both equally open at the outset. By some inches. Otherwise, it works beautifully.

 

[J_J]

Are you using a diverter valve?

Does one lid close first and then the other, or do they both work together?

One cyl might be leaking.

 

[kevin37b]

They do work together but hit relief pressure separately to compensate for odd shaped logs , branches etc . You have 2 circuits on one joystick . Leaking off is not a concern . I have seen new machines that leak off and older ones that do not . Hope this helps .

 

[J_J]

I am not sure I understand your answer on separate relief.

There is one relief for the loader valve.

If the two grapple arms are in parrallel, the one with the least resistance will operate first, and then the other.

As far as relief pressure, both grapple arms have to be developing max pressure for the loader curl function to go into relief.

If one of the grapple arms descends over night, then there might be a leak in the piston cyl seals, or through two valves spools, the diverter valve spool and the curl spool.

 

[TractorLegend]

I'm trying to wrap my head around how one cylinder could shrink down and not the other- this would suggest it's not a leak down of the valve system, since it's shared?
And is there check valves in the cylinders that hold pressure? Or where would the fluid go if there's no external leak? My grapple is new and I'd like to know if this is a warranty issue. That's what I'm getting at. :~}

The added on grapple control on my Kioti does plumb off the loader valve, it appears.
Both lids close and open in unison- they are not operable independently. They plumb together at a tee and two hoses plug into the tractor.

 

[J_J]

In a parrallel situation the cyl with the least resistance will operate first.

You could remove both of the cyl rod ends from the grapple arm and see if they both operate the same. Leave the base end attached.

One cyl could leak down.

You could install a hyd [ gage ] in each cyl and see if each cyl can develop relief pressure. Plug the other cyl while doing test.