Case 580 SK - Slow Bucket rolling

I am having a small problem with a Case 580SK Backhoe. The tractor has low hours (about 3400) and everything works great except....

When I roll the bucket back (pulling left on the control arm), the bucket rolls VERY slowly - almost like its not getting any fluid through the cylinders. If I increase the RPM's it goes a "little faster", but still nowhere near the right speed. Everything else works great (including rolling the bucket forward), so I suspect my pump is ok and the problem may lie in the control arm valve?? I would appreciate if anyone has any troubleshooting ideas and/or tips...

Thanks,
Bob

Make sure the anti roll back linkage is correctly adjusted and not preventing valve actuation.

Along with the linkage from the lever down to the valves for wear, or bending.

If you follow the linkage to the valve in roll back position the valve should be fully actuated.