Rear Brakes Overheating.

[Rockfiend]

Looking for a little direction with my daily, 2009 Passat estate. About 2 months ago, my drivers rear pad was metal to metal, even though they were less than a year old. While changing the pads, I damaged the rubber boots on the calipers, but it all went back together fine. After a couple of days, I noticed that the rear brakes were considerably warmer than the front brakes but thought it was maybe down to the calipers/new pads. I ordered new calipers/carriers and another set of pads and replaced them about a fortnight ago. No issues with replacement. Drove about 250 miles last Sunday, no issues but noticed that again the rear wheels were much warmer than the fronts (no discernible heat in the fronts at all actually) Thought it was a bit strange but as usual, id let it go until something happened. Last Wednesday, driving home on my 10-mile commute, after about 8 miles hit traffic and braked slightly hard. Almost immediately had plumes of brake smoke from the pass rear wheel. Drivers around me alerting me to the fact also. I managed to pull into a car park and immediately jacked the wheel up. No bind whatsoever. Let it cool down for half an hour and drove home. Next morning when I got to work, I checked the brake disc temperatures, and the fronts were 40 and the backs 80. This morning, same commute fronts 40, back 130-110. I’ve tried not to use it too much until I get to the bottom of it but I’m at a bit of a loss. Any ideas what could be causing it? What decides the brake pressures to the rear? Does it have like an old-fashioned load sensing valve? Or is it controlled through the ABS. Any advice greatly appreciated. I’ve had the car for 8 years and just hit 200k and its been good to me but thinking it might be time.