2018 GC1720 - Does your loader leak down while tractor is in use?

[oosik]

I would say that leak down is not normal. I purchased my 2009 Kubota M6040 new. It's now ten years old. I can leave my VERY HD Rhino rear blade elevated and over the period of a week - it will not drop, even an inch. Same with the 820# Land Pride grapple on the FEL.

However - when I'm done with the tractor and back it into the carport stall - I ALWAYS lower both the grapple & rear blade completely down. Both implements rest on chunks of log - up off the ground. Purely a safety concern. I came around the corner of the carport and walked into the lower teeth of the elevated grapple. Only ONCE...........

 

[GeneV]

Can loader cylinders be out of sync or something like that?

It would be by pure chance that pair-mounted cylinders would be completely in sync without needle valves mounted on each port of the cylinders and adjusted to synchronize movement. And even then, to keep them exactly in step with each other, you'd have to go back and recalibrate as the seals and bearing/piston rings wear on each cylinder.

 

[the old grind]

When cylinders are paired hydraulically, they are both bottoming/topping out in sync as much as what they're connected to allows. Metering would only affect cyls not connected mechanically, such as dual grapple lids.

One cylinder being loose at pins means that the mount spacing may not be as precise as the length of the cyls. I suggest that if the curl cylinders were switched from side to side that the same side would be loose at the pins, not the same cyl. If not, the cyls aren't perfect twins. Twisted loader arms could produce a similar symptom. :2cents:

 

[Snobdds]

Mine will drop down a bit. There are no check valves in the hydraulic plumbing to prevent this.

It's normal and fine.

 

[Nacademus]

When cylinders are paired hydraulically, they are both bottoming/topping out in sync as much as what they're connected to allows. Metering would only affect cyls not connected mechanically, such as dual grapple lids.

One cylinder being loose at pins means that the mount spacing may not be as precise as the length of the cyls. I suggest that if the curl cylinders were switched from side to side that the same side would be loose at the pins, not the same cyl. If not, the cyls aren't perfect twins. Twisted loader arms could produce a similar symptom. :2cents:

I haven't lifted anything I feel to be too heavy or in an awkward manner. Certainly nothing has happened to a point where I would remember such an event. I don't even have 80 hours on it, yet. I always hoist from the center using my two bucket hooks to triangulate the load vector to the middle. The only thing that I can remotely recall possibly having a chance at twisting the arms is when I tried to use my Piranha Tooth Bar to pluck a very small tree out of the ground after pushing it over. Even during that, I centered the tree and never used the corner of my bucket. The loader did deadhead that time, though-but it was already flat. Who knows?

 

[4570Man]

It’s normal to drop a little bit but an inch every 10 minutes it pretty rapid for a almost new machine.

 

[Nacademus]

It’s normal to drop a little bit but an inch every 10 minutes it pretty rapid for a almost new machine.

I AGREE!!! Tractor is too new to be behaving like this. I even made sure to center the loader ram to alleviate the chance of debris at either end causing the seal to fail. Something is definitely going on, I just wanted to know if others have this experience. Maybe its just shoddy build quality. Nowhere should a leak-down of this much in a short amount of time be within acceptable range. ¯\_(ツ)_/¯

Sure, well used machines can wear so out leak-down is expected but I've noticed this for over 40 runtime hours-and that's only when I started really paying attention to how frequently I would need to re-curl the bucket. I began force myself to consciously remember having done it while in use because I thought I was going insane.

 

[GeneV]

I never paid attention if the loader bucket does it, but my backhoe boom definitely drifts down at about that rate.

 

[Nacademus]

I never paid attention if the loader bucket does it, but my backhoe boom definitely drifts down at about that rate.

Mine too. I accept that. Its a lot more weight and its got provisions for pinning it up. Loader, though... if ANYTHING on a hydraulic system should be stable and static, it'd be that. I would hope, anyway.

 

[GeneV]

When cylinders are paired hydraulically, they are both bottoming/topping out in sync as much as what they're connected to allows. Metering would only affect cyls not connected mechanically, such as dual grapple lids.

You're assuming that once the hydro lines leave the valve, there are no variables to influence the stroke speed of dual-mounted cylinders, but there are. Differences in the length of hydro lines to each cylinder, one having a tighter bend radius than the other, a slight blockage in one line from a bad crimp where it attaches to the fitting, all sorts of things have an effect.

And that's just the hydraulic lines, the cylinders themselves also have their own quirks which could have an effect on how fast they stroke with same volume/rate of fluid...seals wearing down at different rates, tighter/looser bearings and pistons, again all sorts of stuff.

All of this is why sophisticated fluid power systems employ metering. Our tractors' hydro systems simply don't need to be spec'ed out to that level of sophistication. In reality, one cylinder gets there first, the other one meets up soon *enough*, and it all works out fine.

If you wanna see an example of that, next time you go to dismount your loader, play around with raising/lowering the arms after disconnecting the loader and/or measure distance loader arm to ground after it's been sitting a while.