Uneven pad wear

[neirbot]

I posted this on m.net as well, but I'm guessing folks here will have some insight.

Recently greased my slider pins and just noticed that one of my rear outboard pads is only touching a section of the rotor. I used chalk lines on the rotor to confirm what I thought was the case. I tried removing the pads and cleaning with an Emory cloth with no luck.

I'm puzzled. Any thoughts?

[OZMDD]

The NC rear pads have a round metal nub that needs to be aligned with the slot in the piston or it will sit at an angle. Betting that's your problem. Make sure you rotate the piston to make the groove perpendicular to the pad axis.

[neirbot]

I'll bet you're right, and I can't believe I didn't remember that from last time -- thanks. It must be luck that the other side lined up correctly.

[OZMDD]

I killed half of a rear set of HP+ this way, and the car was braking like shit too and it nerverr occurred to me to check, so don't feel bad. The reassembly process of a brake swap always tends to get rushed. I've had to go back and put on clips tons of times. Hope that's the fix.

[neirbot]

Yeah, hoping my pads aren't spent, but I haven't driven too much on them in this condition.

[neirbot]

So I checked the pad/piston alignment and it looks like it was off. I reassembled and went for another drive -- no luck, but I'm guessing the pads are hosed and the rotor might need to be turned.

[OZMDD]

Rotor is probably fine, but pads are toast.

[neirbot]

Yup. So do folks generally stick with OEM pads for street and autox?

[OZMDD]

It varies. I tried a bunch of pads and found the OEM Mazda pads were better than any other for street/autox, and don't dust/squeal. For track days, I had a spare set of OEM rotors and some Cobalt pads that were fantastic on track. Never faded, even at ECR.

[neirbot]

Thanks - you've been a big help.

[OZMDD]

NP - that'll be $39.95.

[neirbot]

Replaced the pads and rotor... all is good now.