John Deere 3020 squeal

[Grant Q]

Tonight I replaced the hydraulic coupler bushings on my gas 3020. Once I put it back together I had it running and revved it up. After a few seconds this high pitched squeal came from the front. Tractor was not moving or in gear. I have never heard that noise before. I shut it off and turned it back on and the same thing started up again. Any idea what this is? I’ve never seen it leak fluid from that area.

Any thoughts?

Thanks!

 

[rustred]

Alternator belt ?they make a heck of a squeal with a low battery and a loose belt.

 

[Tx Jim]

Ditto tighten fan belt