Haven't ever done it to a Volvo, but I've maintained almost 40 years worth of front disk brakes on VW vans.
There is no need to live with brake drag on these or any other similarly designed disk brake.
With them it was most important to clean the crud off the insides bores of the cylinders, and also make sure the piston (not "pucks") sides were smooth and free of rust, scale, scratches and scoring.
But the most important part was the seal. It gets hard and inflexible with age, and especially heat, and must be replaced. The seal actually is the part that pulls the piston back ever so slightly into the cylinder when the pressure is realeased, thereby allowing the brake pad to disengage with the disk.
I have actually on occasion dismantled everything just to change the seals after a trip in the mountains when I know I have cooked the front brakes a bit too much.
Doubles or triples the life of the pads.