A variation on this is that I drove through a low water crossing. It was concrete that had a lot of moss/algae growing. Being curious about the behavior of the ABS, I lightly applied the brakes, knowing the wheels would slip on the algae. It made loud noises as if someone was hitting the wheels with a hammer. Is this normal?
I got out and looked underneath to make sure something hadn't come loose or I was dragging something. Everything appeared secure. No noise the rest of the trip.