JD 46BH relief valve

[rtm038]

Hello all,
I originally tried posting this question in the JD forums, but got no responses, so I'll throw it out to the hydraulics gurus. I have a relatively new 2520 with the 46BH and it seems that every time I use the backhoe, I'm constantly setting off the relief valve when digging through rocky soil or trying to bust the roots of small (under 6" dia.) trees when doing stump removals. Is there a way to check the relief valve setting for the backhoe controls? Is there only relief valve for the entire backhoe or does each valve block contain it's own valve? The reason I think the relief valve(s) may not be set properly is because my 2520 would struggle a little if I tried to do what the 2320/46BH set-up does in this video:

YouTube - Removing Stump with JD Tractor - Part 2

Also, if you watch that video, you'll see that the operator is able to lower the boom and extend the stick at the same time, while pushing over the stump. Now I know that working 2 functions at once takes practice, but mine doesn't seem to want to perform in this manner no matter how much I practice. Is it me or is my machine not providing the sufficient hydraulic flow?

Any help or info would be great

Thanks
Ryan

 

[Cocre]

According to the hydraulic schematic there is a circuit relief on the boom and dipperstick valve sections, plus a main BH system relief valve.

On my JD 3320 with a 447 BH with the engine under 2000 rpm it is not unusual to only get one function at a time from the hoe. At higher rpms you get more oil flow and more combination movements. Speed is also increased.

All in all, my machine operates like you see in the video. With small hoes you got to work at getting some stuff out of the ground. Sometimes I have to start 5 or 6 feet out from a stump before I can bust through the roots. On hickory trees you are in for a battle for sure.

 

[Gizmo2]

Don't know about the relief valves but I will say tree stumps are tougher than you think and are not these small tractors best friend. I would rather cut a tree stump to ground level than dig it out with my tractor BH but I have done plenty.

 

[kennyd]

If you buy a gauge and some misc. fittings then you will be able to check what the PRV is set for. I am not that familiar with the valve stacks used on the hoes...