Hello Chris. Yes, interesting. It wouldn't at all surpise me if the change away from stepped pistons on Ate rear brakes coincided with the introducton of ABS brakes. The entire brake system had to be re-designed and re-balanced from a dual triangular semi-redundant brake circuit system (that Volvo helped pioneer) in order to support the dual front and single rear brake circuits used with ABS brakes -the fronts can sense and pulsate left/right while the rears can only sense together off the drive shaft and pulsate together. That meant new caliper designs all around, most notably the front calipers moving from a four piston design to the more modern single piston floating clam shell design. While this may have been true of the 740 series, I have my doubts about the 240 series as I've yet to see anyone mention non-stepped Ate rears in the later 240s, some of those later years supposedly having ABS. I'd be interested in hearing thoughts from others on that theory (Art?).
--
Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now