Mazak QT20 spindle hot when not run

I noticed this about a week ago when I was putting a new bar in the feeder, the spindle in the back of the machine was Hot, maybe 140-150 degrees. As I've done before, the parts are coming out OK so I'll completely ignore it until I have time to figure it out, or it breaks. So yesterday morning being the only one in the shop, as is habit, I fire up all the machines when I get there, I got busy setting up one mill and running another while the lathe sat there waiting for my attention. When I finally got around to it, the first thing I did was go and stick a bar in since I already had the tools in and the jaws cut, and the spindle was HOT, not quite as hot, but hot, maybe 120-130 degrees.

I figured, hey its not the bearings, the machine hasn't seen a spindle rotation in 12 hours, the spindle wasn't locked down and besides, its a belt drive, so that can't be the problem. As far as I know it doesn't have a spindle chiller, so it can't be pumping hot cooling fluid to it(it most likely would throw an alarm like the other mazak we have), so now that I'm home at a reasonable hour and awake enough to type, anybody have any clue what this is? I doubt that it is possible that the machine is retaining that much heat over night, though it is warm in the shop right now, holding over 90 all night when its closed up, cooling to about 80 when its opened in the morning, and pushing 100 during the day.

Any ideas?

could it be hot hydraulic oil from the draw cylinder for the chuck? that's usually at the ass-end of the whole headstock. disregard if you are using an air chuck. or the bearings (if any) in the draw cylinder?

Hmmm yeah it is a hydraulic chuck. Could the hydraulic pump be going to hell and heating the oil that much? It never got that hot before, but, I guess that the hydraulics are the only thing moving in that area when the spindle isn't turning, I think I'll check in the morning if there is a cooler for the hydraulics and how clogged up with crap it is, if it has half the dirt and oil in it as I do that could be a problem, thanx, that one never even crossed my mind.