Again, not being able to see a schematic of your system, impossible to be accurate in telling you what to do. However, i'll see if i can't describe mine, and perhaps you can figure yours out on your own. For the record, there is plenty of reading here on the subject if you want to spend some time reading. When i was looking for help installing my loader, a former member (MadReferee) help me tremendously by making me learn about my hydraulic system...... so that i could plumb it myself.
Pressure line comes from pump back to hydraulic block under the seat. Then, pressure leaves the block and goes to the loader valve, which has an in, an out, and power beyond (i'm leaving out the work ports that control the loader cylinders).
Pressure from the hydraulic block goes to the IN port on the loader valve.
The OUT port on the loader valve goes back to the sump (reservoir) on the side of the transmission case.
The PBY port feeds a hydraulic hose that then goes back to a quick connect (female on my tractor), which is connected to the IN on my backhoe valves.
Fluid comes OUT of the backhoe and goes to another quick connect (female on backhoe, male on tractor).
From that quick connect, a hose then goes forward, back to the hydraulic block...... and powers the three point hitch.
When the backhoe is removed from the tractor, the tractor MUST be shut down, and the female QC MUST connect to the male before restarting the tractor. This completes the circuit with the backhoe removed from the circuit. Failure to reconnect those hoses before starting the tractor again will cost you lots of $$$$$$$$$$$$$$.
The only place you can have a T, is the line(s) returning to the sump (spent fluid).
For instance, if i had a valve at the rear of the tractor to control, say for top-n-tilt on the three point, my circuit would come out the loader valve (PBY), go to the IN on the aux valve.
OUT from the aux. valve would T in with the OUT from the loader valve (as they are both "spent" flud)..... and they both dump back into the sump.
PBY from the aux. valve would then go back to the QC and into the backhoe.
I cannot comment on how your power steering ties into the system, but hopefully you can figure that out on your own. Perhaps it would be visualized easiest if you draw a picture of your tractor, and used different colored markers to make diagrams of your hydraulic system. You could use different colors for high pressure, and return lines.
It my seem confusing at first, but if i can figure it out..... you certainly can too !
FWIW, my Yanmar system should be virtually identical to your Yanmar built Deere (except i do not have power steering).
Hope this helped !!
