Disc brake keeps making ping-like shudder I have a commuter bike with Tektro MD-285 hydraulic disc brakes. I commute about 14 miles every day (7 in, 7 out) in most types of weather, but I am not a performance cyclist by any means. It's just a good way to get to work. For the past few months, I have had a bit of a squeal and a shuddering noise that I can feel through the handlebars on the front brake when I brake it hard. When slower there is really little to no noise. I cannot for the life of me figure out what is going on. Here is what I have tried:


Sanding down and cleaning new pads and rotor. 
Getting new pads and rotor and going through the bed-in process.
After replacing, pushing the pistons back in on the brake to try to ensure they are parallel and the whole pad is hitting the rotor. 
Made sure the headset was not too loose. 
Checked the AL fork for any cracks.


Any other ideas? Worth bleeding the brakes?
Replaced the brake and all is well. My guess is one side of a piston was being pushed out with more force than another.