[Rwillia4]

Rotors would be the first thing I would check. If it is also change the brake fluid and make sure the calipers pistons are moving freely...something caused it.
Then
Tires- they might be wearing uneven or out of balance, it is difficult to check without equipment
Alignment- Toe could be off, too much under braking
Control Arms- Check bushings and bolts
Steering Rack- Just check to make sure nothing is coming loose