I've had problems in the past with ABS light on, apparently the sensors were trying to read a loose ring. This resulted in a hideous grinding, lack of braking efficiency and the effect of the pedal pushing back at you when you brake hard. Eek!

I got that sorted and only had it mildly (now and then) when pulling up to a stop, until now. Whether connected or not (after replacing the rear caliper seal and piston) it's back. BUT no ABS light and it only occurs on violent emergency (test) braking. If I firmly brake over approx 200yds (ish) it doesn't occur. Hmmm.

But when it does...(!) it's a bit disturbing.