JD 4240 hydraulic remote adjustments?

Baler door would not stay closed. Found tractor would not maintain pressure on any of the six hose connectors. Mechanic installed new ISO conversion on one pair. No change. This coupling had not been used since the tractor was purchased years ago. Wanted more ISO connectors anyway.Then installed seal kit in control valves. Worked great.
3/4's of a roll later the door is cracked open. With a gauge we figured out the tractor is slowly pressurizing the return line.
If the control lever on the side of the control valve is moved back slightly it dumps this pressure.
Can anyone post adjustment procedure in this unit or just some good advise?

I know it is heavyequipmentforum not ag. Some of my best help has come from here and I hope I have helped some others.
Sometimes professional help is cheep. A local independent shop baled me out. Had the spools with teflon seats and special home made tools. Home made tools were about 40 years old.
We are rolling!

Good to hear!Thanks for the update.