Just curious as to why the rear brakes would have been changed at 31,000 miles before the front brakes? Is this common with these cars? Maintenance did this curing CPO. I'm awaiting maintenance records, but was curious.

 

Rear brakes wear faster than front brakes on newer cars. The portioning valve has been adjusted to send more braking power to the rear. This goes for more makes than just Volvos.

 

yep. with ABS there's no worry of locking up so by changing the bias, manufacturers can reduce the nose diving down on a hard stop for a better driving experience.