Excessive brake dust on one rear wheel

[MME1122]

I have an issue where my left rear wheel has a ton of brake dust, much more than any other wheel. It's honestly ridiculous my whole wheel was just brown. But that makes me think something is up with the brakes on that wheel. The right side has what I would consider a normal amount of brake dust, but it is more than the front wheels which I also thought was weird. Usually the fronts get dirtier because there's more braking load there, correct?
Any ideas what could cause this? If the rear brakes are wearing unevenly, what kind of issues can that cause? The car sometimes feels like it's pulling to the left slightly on the highway.
I have ECS stainless lines and Hawk HPS 5.0 pads, everything else is stock as far as brakes go. I did install an 034 sway bar a couple months ago, that's when I started to notice this. During the install I got the bar caught on the little sensor for that wheel but visually it looks fine. Is there a way to test that and see if it needs to be replaced or something?

[LYKUNO]

Sure sounds like a caliper is stuck, or the e-brake has not released. You didn't mention how many miles you have on the car (or the current set of brakes). Can you jack up that corner with the e-brake off and in neutral to see if the wheel turns freely? Can you scan the car for any codes that are brake/ebrake related?

[MME1122]

54K miles, brakes were new in february so maybe 3-5K on them? I don't have check engine lights but I'll scan it.

With the sport differential, will one wheel rotate or will will the diff just lock up? do I need to jack up both sides?

[LYKUNO]

Did you do the brakes yourself or have a dealer or indy shop do the brakes. If not a dealer, was VCDS used to retract the e-brake caliper to replace the rear brakes (see video below)? With the car turned off and in neutral with the offending wheel jacked up, I'm pretty sure you should be able to rotated the lifted wheel. There won't be a check engine light on for a e-brake fault or code.

[MME1122]

I did it myself, I retracted the e-brake using the Carista app and then used a c-clamp to push the piston back once the caliper was off. I'll do a scan and see what I find and check if the wheel rotates.

If the piston is stuck, would I need a new caliper?

[LYKUNO]

Sounds like you followed the correct procedures. You could also check after driving a short distance if the wheel with the brake dust issue is warmer/hotter than the other side. Also, have you checked for any current fault codes since you serviced the brakes? If a piston is stuck, you might need a new caliper, but others came chime in with their comments (I've not had that problem so don't have a good answer for you). A search on stuck caliper piston may be helpful.

[evanb]

Did you grease the slides?

[jaxkewl]

Did you grease the slides?

this.
a lot of times this is forgotten to grease the caliper pins. happened on my IS300 and wore down my driver side twice as fast.

[MME1122]

Yes I greased the slide pins and the back of the pad and the little rods the pads sit on.
Anyway the car is in the shop so I asked them to look at it for me.
I had a rock hit the supercharger radiator last night and lost all the coolant. Had to have it towed. So I guess I'm killing two birds with one stone (pun intended).