Old thread, but so is the tractor! haha
I just had a similar issue with my '84 Ford 1210. I was moving snow and all of a sudden the FEL & 3pt lost 90% of its hydraulic speed.
Installed a new hydraulic filter. Old one looked like it had seen water and "puckered" -- that's what happens when cellulose filter media sees moisture. Filter looked old anyways.
Drained fluid by removing the banjo bolt on the return line on the side of the trans case. About 3.5gal of murky fluid came out. I poured the old fluid out of the bucket through a steel mesh and found some "stuff". See pic. A pebble, some grass 'n grime, and a plastic bottle seal. I'm betting that was a major culprit. Only 3.5gal came out and I imagine maybe a 1/2-gal was still in the lines, but she was prob a tad low on fluid, too.
Could've also have water in the fluid that was freezing or slushing up. We had a string of -4'F to 20'F weather that lasted a couple weeks then.
New filter, new fluid and VOILA she works like she should again. :thumbsup:
Also if you're having trouble finding a hydraulic filter for this 1210 (or you don't want to pay $45 from the dealer)... you can buy a FRAM CH8765 oil filter, trim one end to length, use a heat gun to pop off the top cap of the old filter, and then JB weld the old end cap onto the trimmed new FRAM. Just make sure you get a good seal and let the JB cure. Better & cheaper and works in a pinch.