It might be helpful if you told us your actual problem. The port reliefs can be easily tested right on the machine.
Dan
I had this in the repair section earlier.
This in previously dug dirt they filled in with all sizes of rocks about 18" down. Nothing that hard.
Tractor sat in the barn all winter and first time out.
Boom was drifting down rapidly.
Then it lost power being able to bring boom in while digging, but it would push out away.
To get it out of the hole I raised stabilizers more emptied bucket by hand and then I could pull it up and lock it to travel to the barn.
After watching YOUTUBE about lower PRV - I moved the swing PRV to the Boom block and Boom PRV to the swing block.
Backhoe worked for 4 hours. I stopped for about 4 ours and came back. It worked for an hour and then boom totally went dead both ways. I emptied bucket by hand . With backhoe running put a bungee cord on valve handle to hold back position an took my other tractor bucket and easily lifted boom to be able to lock it in place and drove back to the barn.
*. There is now a minor amount of oil under the valves. None before switching valves.
It's been sitting in the barn for 2 days now.
Curious why the upper PRV is so much more than the lower one.