Damaged Rotors?

[jlrv]

Went to the track 2 weeks ago and front rotors have shallow grooves and "stained". Guess I was too hard on them. I have braided lines, motul 660 and hawk hps pads. Are they damaged? Should I get new rotors?

[charlietuna]

did you bed them in or rather burnish them prior to your track day? I would consider re-surfacing them and then burnish them as if the pads were new. Try this before you buy new rotors.

[jlrv]

I did the bedding process as described by hawk. I didn't really feel much difference between the hps and the stock brembo pads. If anything I think the breaks performed better on my previous track day with the stock pads.

[Stephen12ZL1]

Stock Brembo pads (Ferodo) are quite good. Those streaks are just surface contamination of brake material from the Hawk pads. Since you just swapped the brake pads and did not resurface or replace the rotors, you had an issue with the Hawk pad material differing from the stock pad material. That surface is not ideal and your brake torque was not as good as the stock pads because of that. Your "upgrade" was actually a downgrade and stock pads would have been much better unless you did a rotor swap at the same time ($$). I went through the same issue when I tried EBC yellow and they sucked with stock pad material embedded in the factory rotors. Finally, I swapped the rotors (Amazon has the best price) and went with a much more aggressive pad Hawk DTC-60 and it now stops better than stock. Only issue with a track only pad like the DTC type is the brake dust is horrible and can be corrosive if it is left on the stock wheels.

[jlrv]

Originally Posted by Stephen12ZL1

Stock Brembo pads (Ferodo) are quite good. Those streaks are just surface contamination of brake material from the Hawk pads. Since you just swapped the brake pads and did not resurface or replace the rotors, you had an issue with the Hawk pad material differing from the stock pad material. That surface is not ideal and your brake torque was not as good as the stock pads because of that. Your "upgrade" was actually a downgrade and stock pads would have been much better unless you did a rotor swap at the same time ($$). I went through the same issue when I tried EBC yellow and they sucked with stock pad material embedded in the factory rotors. Finally, I swapped the rotors (Amazon has the best price) and went with a much more aggressive pad Hawk DTC-60 and it now stops better than stock. Only issue with a track only pad like the DTC type is the brake dust is horrible and can be corrosive if it is left on the stock wheels.

Did you replace with stock rotors? Would resurfacing reduce the life of the rotor?

[*007]

Simply remove pads, use orbital sander on all rotor sides, put same hawk pads back on. I don't think you'll have issues if you do that and burnish in again.

[Stephen12ZL1]

Originally Posted by jlrv

Did you replace with stock rotors? Would resurfacing reduce the life of the rotor?

I did replace with stock rotors which are a two piece design and work well. I decided against anything fancy with cross drilling (known to crack) or slots. Other companies are making replacements that have slots only and that was an option. Resurfacing on many newer car's rotors is not recommended because the metal doesn't have enough thickness to resurface. If they aren't warped, possibly a very minor clean up pass can be made on a brake lathe to get to new metal. The orbital sander method mentioned above may work even though it isn't ideal because it could cause high and low spots. Honestly, I haven't been in many shops that the brake turning machine was used very frequently as most rotors are throw away on any newer car.

[jlrv]

I will probably go with new rotors as recommended above. Thanks for your help.

[Stephen12ZL1]

check amazon.com...they have the best price. I looked at all of the huge GM warehouses and amazon was cheaper by $20ish each. The driver and passenger front rotors are different part #s and a different price too. Now Amazon lists a slotted rotor from DBA for $286 which looks promising. That was not an option when I purchased my replacement stock GM rotors. http://www.amazon.com/DBA52604BLKS-T...brake+rotor+gm

[Stephen12ZL1]

http://www.amazon.com/ACDelco-177-11...+part+20795300

[Stephen12ZL1]

http://www.amazon.com/ACDelco-177-11...gy_auto_text_y

[BmansZL1]

I believe I read in the owner's manual, maybe online, that you shouldn't resurface these rotors. Need new ones.

[ZL1-V]

Years ago thru Stillen I owned the AP Racing six piston calipers and matching rotors and they specifically said no turning of the rotors. Not enough material. That was the advantage of having two piece rotors and still is.

[charlietuna]

You can always buy new rotors. Like 007 said try resurfacing then re-burnish and give it a shot.

I hate the stock pads as they dust like mad but I still use them for street and track.