07 xlt, ~290K miles. When at a light and brakes fully pressed, and in gear, occasionally there is a shudder in the brakes, where the brakes quickly release then activate again edging me closer to the vehicle in front of me. There are no warning lights on the dash or any other indicators. Pads and rotors are fine and don't shake when braking soft or hard. I'm inclined to think it's electronic and pointing to the ABS. Any one have a similar experience? Any ideas on what could cause this stutter?