I just caught this thread . I had the same thing happen with My Iseki about 6 years ago or so . The tractor had been sitting out in an open leanto through below 0 temps & really high winds for several days . It started up fairlly easy but The Hydraulics were whining rather loud & wern,t very responsive .
I Finally got the loader to raise & couldn,t stop it , Needless to say it lifted the roof right up untill it wouldn,t go any higher & it wouldn,t come back down .
The tractor sat that way till the next warm day & has worked fine ever since . Thats the only time it has ever done it & now sits in a nice warm garage during winter months .
I tore down the rest of the shed down this spring , I think theres a thread under Projects , Wasn,t one of my proudest moments .
. I had allmost forgot about it till I read this thread .
. Glad You got yours worked out . Bob