Went in for all 4 corners to have new rotors and pads installed. The fronts were installed. The rear drivers side caliper piston was compressing slowly, and they ran out of time. They said it compressed 3/4 of the way in 20 minutes. One employee said to replace both rear calipers (says replace in pairs, when one goes the other will too). The tech said he just needs more time to compress it and clean it. Says it's wearing the previous pads evenly, so it should be ok. The passenger side rear brake had not been looked at yet. They put the rears back together (no new rotors or pads), and said to come back tomorrow when they have more time. They test drove it around the lot and when returning it to me the "Check AdvanceTrac" message came up in the display, and a blinking yellow AdvanceTrac icon is on the top middle of the instrument cluster. Codes were checked, none found. The "Check AdvanceTrac" message was gone, but I still had a blinking yellow AdvanceTrac icon. They told me to bring it back tomorrow. On the way home the AdvanceTrac icon blinked the whole time. I turned AdvanceTrac off and on, and then left it off driving home. Felt like a brake pulsation all the way home, even when not applying the breaks...more noticeable at speeds 40+. If the piston is not moving well, I would think a caliper rebuild kit would be in order (if they do that). Should I just tell them to clean it, order a rebuild kit, or get new calipers for the rear? Would the piston not compressing freely cause a yellow blinking AdvanceTrac icon on the dash now? (I've read most of the forum threads about AdvanceTrac... this seems to be a different problem and related to current brake work).