Bluish rotor discoloration: failed tech inspection? (pic added)
03-26-2006, 10:23 PM
#31
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Since this thread has gotten the attention of almost all Pagid Yellow Rennlisters, does the following qualified as a "Bedding screw-up" that might leaad onto pad malfunction?:
After I installed the RS19 on the front of my 997S (same brakes as 996TT) I proceeded to bed-in the pads. However, since I started moving the car one of the pads seemed to be "stuck" as the car didn't roll on my inclined driveway adn then noticed some excess resistance when accelerating hard. I thought this will cease after a couple of normal brake applications.
I assummed everything was normal after driving for 5mi on the highway, and proceeded to do the bed-in runs. Everything seemed fine but apparently the outer left front pad got stuck agains the rotor and got overheated, smoking baddly at the first traffic light. After more miles of "friendly driving" I guess the pad go u"unstuck" but then inspecting it at home reavealed that the yellow color in the pad was totally gone and the edge closer to the rotor had a withish ash color....."
The car is braking fine on the street, even from high speeds but I'm concerned about the "track-ability" of the "stucked" pad. Any opinions/advice?
After I installed the RS19 on the front of my 997S (same brakes as 996TT) I proceeded to bed-in the pads. However, since I started moving the car one of the pads seemed to be "stuck" as the car didn't roll on my inclined driveway adn then noticed some excess resistance when accelerating hard. I thought this will cease after a couple of normal brake applications.
I assummed everything was normal after driving for 5mi on the highway, and proceeded to do the bed-in runs. Everything seemed fine but apparently the outer left front pad got stuck agains the rotor and got overheated, smoking baddly at the first traffic light. After more miles of "friendly driving" I guess the pad go u"unstuck" but then inspecting it at home reavealed that the yellow color in the pad was totally gone and the edge closer to the rotor had a withish ash color....."
The car is braking fine on the street, even from high speeds but I'm concerned about the "track-ability" of the "stucked" pad. Any opinions/advice?
03-26-2006, 10:40 PM
#32
Nordschleife Master
I am sure the more experieced guys will chime in shortly with more technical advice but my first question would be did you fully bleed the entire system (especially the location in question)???
03-26-2006, 11:16 PM
#33
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Just a couple comments; some of which are redundant from other posts
1) The blue coloring is only from heat - they aren't 'cooked'; not from stock pads
2) Run the rotors until you get cracks that go to the edge of the rotor and then turn the corner. At this point you need new rotors - reason being that slight warping of the rotor can occur and chew through your pads - a sort of cheese grater effect
3) Keep the holes clean; it will promote better cooling
4) Try running Pagid oranges in front and blacks in the back. It will improve your bias and even slightly extend the life of your fronts
5) Consider getting your next set of rotors cryo'd
1) The blue coloring is only from heat - they aren't 'cooked'; not from stock pads
2) Run the rotors until you get cracks that go to the edge of the rotor and then turn the corner. At this point you need new rotors - reason being that slight warping of the rotor can occur and chew through your pads - a sort of cheese grater effect
3) Keep the holes clean; it will promote better cooling
4) Try running Pagid oranges in front and blacks in the back. It will improve your bias and even slightly extend the life of your fronts
5) Consider getting your next set of rotors cryo'd
03-26-2006, 11:19 PM
#34
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Originally Posted by chris walrod
From the dealers perspective, and keeping in mind liability, I am sure they feel these rotors are toast. Many reasons, but mostly due to the fact dealers probably do not see 'tested' or 'thoroughly exploited'
rotors very often.
IMO, you can probably squeeze another event out of them. However, having a rotor come apart would be very costly..
rotors very often.IMO, you can probably squeeze another event out of them. However, having a rotor come apart would be very costly..
03-26-2006, 11:20 PM
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Originally Posted by LVDell
I am sure the more experieced guys will chime in shortly with more technical advice but my first question would be did you fully bleed the entire system (especially the location in question)???
03-26-2006, 11:28 PM
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Originally Posted by LVDell
Sorry RJ.....I was chiming in for the post gomez had. I should have done the quotes 
Nonetheless, glad to see you bleed properly
Nonetheless, glad to see you bleed properly
Dell, this will be your "rotor saga" soon!
03-26-2006, 11:33 PM
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Originally Posted by cgomez
The car is braking fine on the street, even from high speeds but I'm concerned about the "track-ability" of the "stucked" pad. Any opinions/advice?
It's unlikely, but I'd give that rotor a good lookover and take the pad out and inspect it for any signs of damage. You might need to sand the pad down enough to fit or take the anti-squeal shims out.
Cheers
03-27-2006, 12:45 AM
#39
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Anti squeal shims??? How many of you run with 'em? I guess the reason I ask is that I swap between pads before going to the track and installing shims EVERYTIME would be a pain.
03-27-2006, 02:49 AM
#40
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Originally Posted by cgomez
Since this thread has gotten the attention of almost all Pagid Yellow Rennlisters, does the following qualified as a "Bedding screw-up" that might leaad onto pad malfunction?:
The car is braking fine on the street, even from high speeds but I'm concerned about the "track-ability" of the "stucked" pad. Any opinions/advice?
The car is braking fine on the street, even from high speeds but I'm concerned about the "track-ability" of the "stucked" pad. Any opinions/advice?
The pad that was stuck should be sanded lightly to take off any glazing, then reinstalled. The color change on the surface of the pad and even the areas around the backing the pad is affixed is quite normal, once the pads reach hot temps. A new set of yellows will appear grayish after a track day...it's just yellow paint, not high temp paint either. The brake dust and heat conditions will discolor the paint used to color code them. Upon removal there will still be some yellow left on the back of the pad backing plate.
I'm still curious why the symptom of 1 stuck pad appeared.
Austin
04-03-2006, 12:56 AM
#42
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Just got back from VIR and the brakes were fine. The modulation was a little less smooth compared to when the discs were "clean", but they worked well.
The cracks, however, have progressed and the pad smear has increased.
My conclusion is that the stock pads are simply not up to the test. Yes, they were bedded properly.
It's time for new rotors and RS-19s (F) and RS-14s (R).
The cracks, however, have progressed and the pad smear has increased.
My conclusion is that the stock pads are simply not up to the test. Yes, they were bedded properly.
It's time for new rotors and RS-19s (F) and RS-14s (R).
04-03-2006, 11:08 AM
#43
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Couple questions RJ:
1. Why the diff in pads F/R. Are you trying to adjust the brake bias?
2. You don't intend to put NEW rotors and pads at the same time do you?
1. Why the diff in pads F/R. Are you trying to adjust the brake bias?
2. You don't intend to put NEW rotors and pads at the same time do you?
04-03-2006, 07:06 PM
#44
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Originally Posted by LVDell
Couple questions RJ:
1. Why the diff in pads F/R. Are you trying to adjust the brake bias?
2. You don't intend to put NEW rotors and pads at the same time do you?
1. Why the diff in pads F/R. Are you trying to adjust the brake bias?
2. You don't intend to put NEW rotors and pads at the same time do you?
2. Nope. New pads on toasty rotors then later, rotor transplant.
The rotors on the cup cars were looking fresh... and not so stressed. The 996 street car simply has p*ss poor ventilation up front and stock pads that aren't up to the test.
I also saw some really nice slotted setups...