Brake Actuator noise on 2002 Prius

There have been other discussions regarding this program in the Gen II forums, and I think Toyota should have addressed this in the service bulletin aimed at the 2004-2007, all the way back to the early models, since the ABS systems were pretty much all the same. I have a 2002 Classic, and I had the problem where the ABS system was periodically making a "barking" noise, the brake light and alarm would go on, and the ABS system would go offline.

Discussions on here in other forums suggested that the problem could be dirty brake sensors or a bad actuator, but my independent mechanic who has serviced many Priuses found the problem to simply be old brake fluid. He flushed the brake fluid and lo and behold, the problem resolved itself. He said that old brake fluid breaks down and takes on the consistency of water. He replaced the brake fluid with synthetic brake fluid that doesn't break down as easily. I suppose my brake fluid was old.... I had never replaced it since I bought it..

The way he explained the problem, is that that there was unequal pressure being reported by the brake sensors, and because of that, the ABS was thinking that the car was going into a skid and thus setting off the actuator to do its thing.