i bought an old pc300 to build a road up the side of the mountian in colorado. it runs like a top, tracks straight and feels pretty good considering the age. but the curl on thew bucket is weak. i can dig and when i curl it just seems to do nothing unless it pretty easy digging. i can make it fall back when i am raking with it. is there a relief valve on that circut that is bypassing? or maybe the cylinder just leaking by?
It could be the cylinder or circuit relief easy enough. The Dash 3 machines had internally relieved cartridge valves that could cause the main body to crack internally. We used to install the externally relieved Dash 5 circuit relieved valves in place of the Dash 3 units. At any rate follow the lines back from the bucket cylinder to the main control valve. The circuit relieves with be in some king of line with the hoses. You can swap them from side to side and see if it makes a difference.
i wish my service manual would show up. and thanks for the ideas on what to check out john.