I have a MF 1428V and recently have a problem where the three point arms drop very slowly. Even with a heavy rfm or bush hog on the back, they drop ever so slowly.
I poked around the back looking for a valve or a seeting I could adjust and didn't see anything likely.
Kubota L3901, 525 FEL, Woods PRD6000, Woods BB60, and 7' rear blade.
Not familiar with your model, but my 1020 has a knob in front of the seat. Turn one direction and it slows the 3 point drop. Turn the other direction and it allows it to drop fast. I bet you have a valve somewhere that controls yours as well.
I do have a valve! and mine was under/below the seat too. I was looking around the arms themselves.
many thanks, problem solved!