I have a MF 271 and pulled it into the barn a week or so ago and everything was fine. Yesterday I went to use it and the 3-point arms won't lift. The front end loader works fine as does the aux hydraulics. I had changed the hyd fluids about a month ago and found some slime in the linkage strainer which I cleaned. Thinking maybe something had plugged it again I drained and pulled the filter again. The stainer is clean as a whistle. I am kind of at a loss as to what to look at next. Any ideas? Thanks