fatsport

I’m kinda a new guy, been doing this for about a year. Tried some Powerstop Track Day pads on my C7Z. They had some decent reviews. I ran at PBIR last Tuesday and then Sebring on Saturday. Saturday I heard a grinding noise whenever I hit the brakes during happy hour so I shut it down. I had checked for pad thickness throughout the day, there was plenty of pad left.
Had a “race shop” near me put Castrol SRF in before I ran both events. I previously had put in Motul 600 in with help from a friend.
Took the pads off tonight to look at them and the back sides of the pads look like they’ve had brake fluid leaking on them. Did I boil? Did the shop not use the SRF.
Thanks for any suggestions. Trying to run at Daytona this weekend.
I have Hawk DTC-70,60 pads I can put on. I have another pair of rotors that will be here tomorrow.

Supercharged111

The pattern does look weird, but brakes get hot and paint will burn. Not sure this is something you should concern yourself with. I burn brake pad paint myself, pretty normal.

fatsport

The grinding sound is perplexing.
Here’s the stock pads, I had run them for 3 track days before putting the powerstops on and getting the SRF put in. (Had Motul 600)
No signs of burning paint

Supercharged111

Did you get the new pads bed in good? Changing pads but not rotors can be a noisy experience until the new pair has gotten to know one another.

fatsport

I did follow the powerstop bedding procedure, yes.
10 stops from 60, let them cool for a couple minutes, 10 stops from 80, let them cool.
I think I may have found the grinder. The passenger side inside pad looks glazed and cracked. Cracks aren’t bad, but it definitely got hot.

Supercharged111

Is that procedure based on a fresh, unbedded rotor or a previously bedded with someone else's pad compound rotor?

fatsport

They didn’t specify. Are you thinking the new and old pad materials aren’t compatible? Should I buff/clean the rotors with 80 grit sandpaper? I’ve done this before on other rotors. Garnet in 80 grit does a good job of removing pad material

BrunoTheMellow

Those rotors look really smeared. Did you feel as if the brakes were weak even though the pedal was hard?

Smeared rotors means you overheated the pads.

fatsport

It seemed like I was hitting them harder and getting less as the day went on. There’s 3 big braking zones in a row, turns 17,1, & 7. Turn 7 I would slow down from 135ish down to 40, seemed like I needed to move my braking point further from the turn.
I have Hawk Dtc 70 front and dtc 60 for the rear I can put on. Don’t know if I should attempt to clean the ‘smear’ off the rotors though.

froggy47

All looks ok to me.

BrunoTheMellow

Yep . They weren't up to the task. Nah a good bedding will clean it up.

fatsport

Thanks guys. Going to install the Hawks and follow the process demonstrated by Essex:


Lots of great info here:

https://www.essexparts.com/support/learning-center--faq