New to me 5500 Repair ??

[kneedeep]

My 5500 4WD has developed a hydraulic leak at the top of the steering column. It takes a little while to start but it is a steady drip.
I looked online at a parts breakdown, there is no seal at top of column, so it must be in the lower unit.
Any suggestions??

Also, the idle seems too high, anyone know what the correct idle RPM for it is??

TIA