Zebra 3522 Hydraulic problems

Ok so i have an old Zebra 3522 and it has not given me any problems for the last few years well lately the hydraulics have been acting up (3 point does not stay in position and i am constantly having to raise it back up and now my bucket is not raising). Wondering if it is low on hydraulic fluid but i have to be honest i have no idea how to check this? Also does this tractor have a hydraulic filter? Where is it located? What type of hydraulic oil should be used in this tractor? can i just get some cheap 303?

Thanks in advance.

Hello,

Oilcheck: upper side Gearbox in the middle
Filter: also upper side, but under the seat
Oil: UTTO SAE 80W 90 you can use

And you can download a instruktion manual - your zebra is similar to a Zetor 3511: http://www.zetor-forum.de/forum/resources/bedienungsanleitung-zetor.1/

Regards