That very same thing happened to my 5000. When I got it the fluid was chocolate milk. Drained, flushed, refill with fresh fluid. Three time. Running brush hog after 3rd time and everything quit. Suction screen on pump was plugged solid with paint chips,sawdust, and what looked like the remains of one of those desiccant packs. I mean plugged solid. Apparently the previous owner wasn’t picky about the cleanliness of the bucket they were using. I had to split the tractor to get all the dirt out.Loader and linkage work fine when cold however after using PTO for 20 mins hydraulics stop working, any help would be much appreciated