Hello,

I have Shimano Deore BR-M525 hydraulic brakes and both front and rear are making really loud sounds.
The front makes a really high-pitched noise when the lever is pressed hard enough.
The rear is a lower-pitch noise that almost makes the whole bike vibrate.

I've been searching for a couple of hours, and found a number of possible causes, but nothing definitive.

I have recently bled the brakes, which didn't help. Checked to see if the brake assembly was loose, but couldn't find anything.

If someone could help me diagnose/troubleshoot this problem I would greatly appreciate it.