Glad to hear you are back in operation.Ok, I went out tonight while the temps have been in the low 40's today, cranked her up and hydros worked fine. Still tdon't know the culprit but will start looking for water in the hydro system. I'll get back when I figure it out.
In these circumstances you always fear some major failure.
Now that you are operational, for your piece of mind I would just change all the fluid and both filters. Cheap insurance and piece of mind.
When you have not owned the machine from day 1 all sorts of stuff like 90 gear oil could have been added in lieu of the expensive UDT fluid.
Dave
Dave