My 580B has some weird things happening to the boom cylinder's spool valve. First when the boom falls from the transport lock it acts like a suspension and bounces up and down because of the cylinders and digging it will stop all of the sudden when pulling it up, and when I try to raise the backhoe off the ground with it , it will raise it but when I let go of the lever into the neutral position the valve makes a noise and lets the tractor down, I am wondering if there is a seal kit or common fix out there?
I'd be looking at a relief valve or check valve, maybe something in the pilot system, I've seen joystick valves set too tight and pushing too many poppets at once. Got guages?
The bouncing from transport position is normal - nothing to fix there. If you raise the machine with the loader bucket on the ground - the noise being made is the secondary relief dumping pressure - from tring to hold too much weight. Normally if the front bucket is raised off the ground a little, the BH boom hydraulics should hold her up - is your loader bucket on the ground when you try to lift?
When I try to lift the machine with the bucket up or down I can push the lever wait a second and then the boom cylinders start to lift it but as soon as it back to neutral it lets it all back down quickly and Im pretty possible its not the relief valve and what gauges are you talking about