Massey Ferguson 640 Fermec 640b Power Steering Question

[Victorya]

I just purchased a Fermec 460b (very similar to Massey Ferguson 460 and Terex 460). Visually she looks in good shape for a 1999 with 4k hours. During testing the power steering started to pulse/shake while turning the wheel and at one point stopped working. The forward and reverse also went out at that time. After fiddling with it got it to move but power steering still jerky. We found a puddle of hydraulic fluid where the tractor was parked in the dirt. I took a gamble its just a leak and not more serious and bought her anyway. It appears the power steering pump is on the lower right side of the motor and is driven by the gear housing up front. There is a filler neck/cap on the left side of the tractor for the gear housing, but I see no dip stick or way of knowing how much fluid is in it. Do I fill it until I see fluid covering the gear I can see from the filler? Also what type of fluid do I use? and is it the same fluid throughout the tractor (not motor of course).
Thank you.

 

[Agvg]

Picture of the pump? If is a classic MF pump the cap is the level indicator.

 

[Victorya]

I was able to located a service manual and an owners manual. It turns out this is not only the power steering pump but also the pump for the transmission. They both share the same hydraulic oil stored in the transmission and rear axle. What I thought was the power steering fill point is the motor oil fill location. Also looks like according to the manual, originally both the motor and the transmission used 10w-30 but Universal Hydraulic fluid can be used instead. See last image showing fluid specs. Please correct me if I am wrong about any of this.