Was driving slowly and coming to a stop. The brakes started chattering - a rapid fire grinding type noise- and the brake pedal started pulsating. It happened a couple of times. Ran fine otherwise: braked OK, warning light off, and fluid level OK. I replaced the pads, PBR Deluxe, about six months ago and was running fine since, until today. I was told that these symptoms are due to ABS trying to find itself when tires slip. I mainly want to get confirmation of this and make sure that something isn't seriously wrong with the brakes. I don't think I was pumping the brakes out of habit and have good snow tires on. Any responses much appreciated.

Guri R