[turbo6justin]

Just put new Centric high carbon rotors and Powerstop Z23 pads on a new to me e93 335i. Did the bedding procedure per their instructions and drove it around normally for maybe 50 miles in total so far. The drivers rear rotor looks and feels to the finger very bad, the other 3 look the same and perfect. Normally I would attribute this to a sticking caliper but I took it out for a brisk drive and that rotor is no warmer than the other rear (checked with a IR thermometer). I also drove without touching the brake and then checked and the same no extra temperature in that rotor both were about 10 over ambient so basically cool. It is not dragging or noisy. Thoughts?

Hopefully I can get the pictures linked here. Holy big pictures, sorry about that. The first picture is the questionable rotor, it looks and feel like there are a lot of deposits on the rotor, it feels rough to the finger or fingernail. The second picture is indicative of the other three, they all look great.

Many thanks in advance.

Justin

[335i54n]

just need more braking miles put on but not too abnormal

[TH4X]

The disk looks fine like 335i54n mentioned and just need some extra miles worn in.

[charlie_m]

No, something is definitely different there on the LR. If you can still see factory cross-hatching on three disks, and one is grooved like the first picture, then either it's a bad disk or bad set of pads. Well, maybe not bad as in defective, but different disk material or pad material, or different lot numbers.

Do both sides of that grooved disk look the same?

I would try your heating tests again, maybe a little more aggressively like 2-3 stops from high speed, near threshold braking. If the temps are similar between left rear and right rear, then it's probably safe to continue using, but keep an eye on pad wear & rotor thickness on that corner. Temps front to rear may be different.

If you are really curious you could swap rear disks side-to-side and see if the LR pads mark up the better looking RR disk.

[Wolf 335]

Jack up the rear at the diff and spin the wheels by hand. You will know if your caliper is stuck.

Car will need to be in neutral so make sure the front wheels are secured and that car wont roll on you.

[Welcome to NBA Jam]

Pretty normal. It'll take a while to fully bed in. Give it a solid month of driving and you'll see it get more uniform.

Btw: How do you like the PowerStops so far? I need some new brakes on my other car but the brake options are kind of limited for whatever reason. PowerStop Z23s are available though. Curious about the dusting and performance.