So after having my car come from a shop after fixing my diff from falling liberality out of its bolts. I had experienced an issue to this day. The brakes for some reason when i press it jumps back up at me with a whining sputter sound. It vibrates as well when pressing like its not wanting to slow down kind of like when you slam on the brakes hard and the abs goes into action but it is happen pretty much on the start of the pressing. It does not do this much when at low speeds of around 20-30 but anything higher and its considerably noticeable. I have 2 things in mind that could be doing this but idk what it is. 1 is the rotors because its somewhere in the fronts and the 2nd is the brake line leaking but no noticeable leaks as of yet.
So what is your guys opinion of whats going on?
Note: Rear rotors where changed out last year and the fronts where never changed. So i'm running on 105k miles on the front rotors with pads changed out last year.

 

I would check the rotors first. Could be warped or you could just have pad build up in one area.

I always start with the easiest thing and move from there.

 

Sounds like a speed sensor got messed up when they took them out of the diff and it's triggering ABS on you. Check the two sensors bolted to the diff by the axles, make sure they are bolted down properly and plugged in, the wiring is in good shape, the wheels on the axles don't have any chipped/broken/damaged teeth on them.

 

Well the thing is that i only hear it up front, not in the rear but if you say so. I will take a look at the sensors.