Massey 180 Power Steering problem

[DJ54]

Finally got the ole' 180 back together yesterday,and decided today to go play a little...

I purged the PS pump, per Bigs Deans instructions, plus made and extended pipe, with vented plug to burp any extra air that may have been in the system,, while driving it today.

With the tractor at an idle, it seems to turn the wheels pretty easy. Turned them full left, and back to full right numerous times, purging the air, and adding oil.

When you increase RPM's, the steering seems to get stiff. Like it's fighting itself. This has the early Saginaw Hydromotor/Power Rack steering system. Apparently they had problems with this setup, and went with a Char-Lynn unit on later models..

Driving it today, if you turned the wheel slow, you can turn it with one finger... Try and do a fast turn, and like it's binding, or fighting itself, maybe in the power rack cylinders... Like one side isn't letting the oil return to the system, as fast as it should.

I see no loss of oil anywhere in the system, and the PS pump oil level is right up there where it should be..

Any idea's..??