Working on my neighbors 1972 JD 2030 68HP diesel tractor for a hydraulic leak. The tractor has a front end loader which is connected under the tractor at the selector control valve for what looks to be the rockshaft control on the right side of the operators seat. I disconnected the hoses to be front end loader, but the tractor is still leaking at what appears to be the selector control valve. Does anyone have a hydraulic schematic for this tractor or parts number list. I don't know if he has a service manual or not. Thank you!!!