Cat 259D Squealing sound

[jloven14]

I have a 2017 Cat 259D that consistently has a high pitch squeal shortly after startup and lasts for about 30 seconds or so. I have changed both belts and also the tension on them. What else could it be? Water pump bearing? After 30 seconds of squealing, it goes away and doesn't do it again unless you shut it off and start it back up. Does it in cold and warm weather. Thanks for any info.

 

[foton]

I had a alternator that would put a load on the belt that it would squeal until it was done with the load of putting back in the battery what the starter took out. but this was on a backhoe with a single v-belt, if your has a auto tensioner I would think this will not apply unless it is weak.