Uneven rear brake pad wear

[mustanger]

I just discovered an issue with some uneven rear brake pad wear. I noticed my rear driver side outside pad was worn significantly more than the others. The pads were Hawk HPS with 44,000 miles on them. The driver's side outside pad measured 3.5-4mm and all other rear pads measured between 7-8mm. I checked rotor temps with my infrared thermometer and found the left rear rotor after normal driving was reading around 120F and the right rear rotor was running around 90-100F. I verified the e-brake wasn't hanging up. It did feel like perhaps the left rear caliper had just a little more drag when trying to turn the wheel by hand on jackstands. I checked the slide pins and found that one of them had some scoring on it, so I replaced the slide pins on the left rear caliper. After this there was no change in the rotor temps. Yesterday I went ahead and replaced both rear rear rotors and pads and installed a new left rear caliper and bracket. I also flushed/bled the brake fluid. I took it out for a drive yesterday to bed the new pads in and when I got back the temps on the left side were still about 20F higher than the right side. I did some searching and it seems there's been a few other posts over the years which reported more wear on the outside pads but with no definitive reason or solution. At this point the only thing I can think is it's due to the axial play of the c-clip set up, or an issue with the brake hose. The car has goodridge braided lines which have been on the car for about 11 years/80,000 miles. I have regularly flushed/bled the fluid. I've never done any HPDEs, but have done a handful of autocrossing events and a fair number of trips to the drag strip although it hasn't seen any of these events for several years now. Any suggestions, thoughts or advice would be greatly appreciated. Thanks!

 

[Marble]

I have replaced both of my rear calipers. I had the same issue with both sides. The calipers are not expensive. The biggest pita is compressing the e brake piston.

I would either leave it or replace the caliper and make sure you bleed it properly.

 

[eighty6gt]

I have found the caliper bracket defective - bad bushings into which the guide pins insert. The caliper then and locks - at least this is my thought. I replaced both of mine because my driver's was bad.

Not a fantastic system, sliding calipers.