We had a 135 years back. Best I remember it didnt have any thing like a filter there might be a small screen at the bottom rear probably right side. you have to unbolt and pull the seat lift arms and all up to get into the lift.
These were built when few people used remote lines. I think in a fairly closed system the metal wear particles settled out. You might have 40 years worth of wear metals.
Are you having problems like hiccups (jumping jerking when your trying to lift) or something?
Thanks for responding, I heard there was a screen, sorry not filter. Also that I could access it though the pto cover. My hydraulics are erratic they will lift up all the way without me touching levers, broke 2 driveshafts this way, also you can lift the attachment and push it down with your hands, it's almost like its in constant float mode. Just like to see if anybody has had this problem, thanks
I have a MF 245 which followed the 135 and has the same 45 HP engine. Mine has the hydraulic filter between seat and left rear wheel, see attached pictures. It is not a spin on type. It is the big canister looking thing in the middle of the pictures. One picture from front, one from rear. Not sure if this helps, yours is a different model.