Hydraulic spill origin

Hey guys another newb question, i had no problems with my gehl 4835 sxt until this weekend, had it parked outside for a while and it did dip below freezing a couple days but no problems with battery or anything. Had to get it up a hill which wasnt easy with the wet ground from night frost (lesson learned). So it took some wheel spinning and a winch but drovw fine after that hydraulics worked fine. I get it in the garage for the winter and next morning theres a gallon of hydraulic fluid on...

Hydraulic spill origin

Hydraulic spill origin