Massey 231 front loader help

[Zeke1eod]

I have a June 93 Massey 231 with a Massey 295 front loader and shaft driven external pump. It's always seemed weak/slow, now it will not lift at all. I checked fluid it was 1 gal low, and white ish milky possible water intrusion, which is odd always kept in dry, not crossing creeks etc. Looking at local dealers for filter screen and gasket. The draft and position levers are in up position and you can hear the pump engage, pto works and it will drive, if I tie loader joystick back and walk to front, pump is turning, I have service manual but hydraulic diagnostic info is weak, what should I look for, any valves on transmission or elsewhere? I have numerous pressure gauges up to 5k psi, where would I plumb gauge into check pressure and what psi should I use? Thanks in advance