1998 Mazda 626 Mazda 626 Brake Problem

Brakes problem
1998 Mazda 626 Front Wheel Drive Manual

I have had a problem with my brakes for a while. When I brake from higher speeds (over 50mph) the brake pedal vibrates and steering wheel shakes violently. The car sounds and feels like an earthquake from the front end, the noise comes from ABS unit or brake cylinder. Sometimes the wheel shakes so much I almost lost control of the car. The power on the brakes is very weak.

ABS doesn't work, if I press the brakes harder the vibration is not so bad but the brakes lock. ABS module doesn't give any fault codes and the light never comes up.

Every brake rotor and pads are changed as well as the lower balljoints, but the problem is still there. When the rear brake rotors and pads were replaced, the problem went away for about a week but then came back worse. Before the change only the pedal was shaking and the earthquake noise didn't appear.

One day I kicked in the brakes hard several times in a row when at high speeds, and the brakes started to work a little better. But the problem comes back in one day.