I HAVE 99 VW Beetle STANDARD WHEN I PUSH THE.

Do you feel a pulse in the brake pedal?

The ABS might be activating due to a tire pressure difference or a crack in one of the "tone wheels" for
one of the ABS speed sensors.

Have a shop look at it. Not much that can be done with this over the internet (need to see and drive the car
to diagnose).

Thomas