I have one of the valves on my backhoe that does not return to center when the lever is released. If I don't manually put it to center, my dipper stick moves just about the same speed as your "bleed down". You may want to check to see if you have the same problem with your valve. Is it just this hydraulic cylinder, or do the others bleed down this fast as well?
My backhoe was delivered that way. I don't think my dealer did a thorough job of checking it out before delivering it. I've already talked to them about warranty coverage.
Mine definitely leaks down, but it's slow enough you wouldn't be able to watch it like that. If I use the backhoe as ballast, I have to lift it up ever 45minutes or so it starts to droop... I use a ratchet strap for the outriggers when not in use or while in storage.
I picked it up from the dealer and installed everything myself. It's definitely an issue with the valves, cylinder, seals, whatever on the backhoe, and not the installation of the power beyond kit right?
Manufacturing defect? I bought it this spring, and I'm 99% sure it's been like this since day one.
I hope Kenny and some of the other hydraulic gurus will chime in on trouble shooting for you, but my hunch is that it relates to the backhoe seals and as you said NOT the power beyond system or your install.
Wish I could be more helpful other than to confirm your hunch that your setup has an issue.
My bet is a bad cylinder, there have been quite a few reported if you search a bit. Get the dealer involved to get it replaced since it's under warranty. No the PB install would have nothing to do with that.
I don't own the 260 backhoe but rented one a week ago. Not normal at all and I bet Kenny is spot on right. The rental I had was rode hard for 370 hours and none of the hydraulic cylinders leaked down over night. The outriggers didn't move but and inch overnight. I'd get the dealer involved