: Heat Spots on Front Rotors...... (PICS)



cbloveday
09-04-11, 09:48 PM
First of all, please disregard the brake dust. I plan to wash the car tomorrow.
I am scheduled for new brake pads on all four corners Wednesday.

I take exceptional care of my car and always look it over many times through out the day.
Recently I noticed both front rotors show signs of heat. It is really bothering me that I can not figure out
how this has happened at 28,900 miles. There is plenty of brake pad left and I have had Brembo calipers and rotors
on previous cars. This has never happened. The rears are fine.

A little History:

1.) I do not road race the car
2,) I am very light on brakes. I do not "ride" them and baby the car on public roads.
3.) Only hards stops I do are at the strip and this is my 2nd Season (Maybe 35 passes in 2 years). I am careful to drive slowly on the return lane and allow brakes to cool before stopping for my slip.
4.) When washing the car, I make extra sure the rotors have sufficient time to cool before water hits them.
5.) I did remove the driver side brake duct last year and re-installed it during the winter, then removed it in April this year
6.) I recently had new tires put on the rims and I noticed at the track that the lugs on the rear where torqued past the stated torque. I wonder if the tech did not use a torque wrench. :(
I plan to bring this up when I return for the service.
7.) Ask them if the caliper sliding pins could be a problem.

So, the condition appeared out of the blue in the last 2 weeks and it shows on both driver and passenger fronts, so I ruled that out as the cause.

The only other deviation from my normal routine since I have owned the car is I parked it the driveway for 1 week. My father was here and his mobile home was in the driveway. I did not have access to the garage. I can't see where that would matter though.

I am wondering if anyone has experienced the same condition (especially the road course, strip guys or someone who has removed both brake ducts).

My dealership is stepping up by offering to replace both front rotors for free, and they are pricey.
I can't say enough about Naperville Cadillac and my relationship with them! The offer was unsolicited.

I plan to have them check the rear brakes to make sure they are functioning properly. I think they would throw a code if not, but who knows. I will also have them check the brake fluid to make sure it is ok.

Below is pics of the front rotors. The blemishes look like thumb and finger prints all over the rotors.


Driver Side
http://i183.photobucket.com/albums/x99/cbloveday_bucket/DSC_0298.jpg


Passenger Side
http://i183.photobucket.com/albums/x99/cbloveday_bucket/DSC_0297.jpg


Driver Side in Daylight
http://i183.photobucket.com/albums/x99/cbloveday_bucket/DSC_0298-1.jpg

http://i183.photobucket.com/albums/x99/cbloveday_bucket/DSC_0297-1.jpg

EuroTrash
09-04-11, 10:59 PM
I am curious but why would you remove the brake ducts? Did you replace them with something larger or did you just leave them off?

If you didnt have the brake ducts on i would expect the rear of the brakes to not get the appropriate amount of air to cool during normal driving, which may be why you are seeing tarnishing on the rotors. Just a guess tho

cbloveday
09-04-11, 11:03 PM
I am curious but why would you remove the brake ducts? Did you replace them with something larger or did you just leave them off?

If you didnt have the brake ducts on i would expect the rear of the brakes to not get the appropriate amount of air to cool during normal driving, which may be why you are seeing tarnishing on the rotors. Just a guess tho


They were removed to allow more air into the engine bay vs being directed at the wheels. My after market CAI is situated in front of the driver
fog light and with the duct removed, it is a straigth shot of fresh air to the filter.

baabootoo
09-04-11, 11:51 PM
Why would you think that they are heat spots? I believe that is one of those myths that's been passed down. I thought technically it is an uneven coating of the pad material. I think that you only need to clean this off, with abrasive brake pads, and rebed the stock pads. Since there is no one pad for all occasions, the permanent solution would be to just get some pads made for YOUR conditions then. Remember, these are pads designed for VERY high speed driving, so at low speeds they are not at their best. Look up this at the StopTech site for more info. I road race mine a lot, and have this discoloration, but it doesn't affect braking. Once I put ceramics on for the winter, and rebed them, they still very clean (no dust either) all winter long. In their own charts, the stock Ferodo pads are NOT considered street pads either.

cbloveday
09-05-11, 12:02 AM
I was told by the dealership that they are hot spots. I thought about rebedding new pads but the dealership offered to replace the rotors and I thought if that is the case, I will do the bedding of the new pads on the new rotors myself. I went to Stoptech while researching the condition for possible causes. I actually bought my brembo cross drilled rotors and stainless steel brake lines from them for my srt8 2 cars ago. My splotching has not affected brake performance to date, either.

Thanks for the reply and I will follow the procedure outlined for performance pad bedding.

BTW, to clarify, the splotching disappears when you put the ceramics on?

thebigjimsho
09-05-11, 12:16 AM
Hey Curtis, when your dealer gives you free rotors, can I have your old ones? They look fine to me...

baabootoo
09-05-11, 12:16 AM
Yep, but I have streaks though as opposed to spots. I rebed each pad set each time I put them on. It's sort of a pain, but I can't fault the experts!

thebigjimsho
09-05-11, 12:21 AM
Yep, but I have streaks though as opposed to spots. I rebed each pad set each time I put them on. It's sort of a pain, but I can't fault the experts!Yeah, I've seen streaks on my rotors after not bedding my pads. I'd imagine a couple runs on the Tail would clean Curtis' rotors up a bit...

gut2727
09-05-11, 12:35 AM
Seems like a case of (if I may BigJim) "too much power".

Look at is this way CB - rotors aren't going to end up happy during repeated atmospheric re-entry.

cbloveday
09-05-11, 07:38 AM
Alrighty then.
I like the "TMP" explanation. :)
I will ask the dealership if I can keep the rotors.
They may want them though, to prove the warranty work.
If I may, I will request, they forward them to THE BIG JIM HOUSE OF BRAKE & TIRE PAIN, for analysis.

Junkie414
09-05-11, 11:40 AM
Mine have a similar look to it but my spots are blue I just assumed it was from 170+mph stops

cbloveday
09-05-11, 12:50 PM
I am sure it is.....

thebigjimsho
09-05-11, 07:54 PM
Alrighty then.
I like the "TMP" explanation. :)
I will ask the dealership if I can keep the rotors.
They may want them though, to prove the warranty work.
If I may, I will request, they forward them to THE BIG JIM HOUSE OF BRAKE & TIRE PAIN, for analysis.No Curtis, no more freebies...

thebigjimsho
09-05-11, 07:55 PM
lulz.

cbloveday
09-05-11, 07:56 PM
No Curtis, no more freebies...

No means yes!