Rotor Spots - Have You Seen This Before?
#1
Rotor Spots - Have You Seen This Before?
Hey guys!
As some of you might recall, I posted a review thread of my Carbone Lorraine RC5+ brake pads. At the time, before the CL’s were put on, I was running GiroDisc Bailout rotors and their Magic pads which I hated. I was experiencing the brake shudder otherwise known as pad deposits or warped rotors. I knew I wanted to upgrade my pads since the Magic pads did jack **** for stopping power, and so knowing that the CL’s were sintered I figured I’d give them a chance to see if they could “scrub” my rotors clean of whatever deposits were on the rotor. To no avail, they still shuddered and I was left dealing with it until I could pick up a replacement set of front rotors.
Now, ever since I installed the CL RC5+, I noticed that my rotors began to develop these circular heat spots. I chalked that up to the pad deposits or heat spots and thought a new set would simple solve the issue. I didn’t actually know if the spots were actually a cause for concern because my rotors already were shot so I didn’t know if they contributed to anything negative other than looking odd.
Have any of you ever seen this before??? These are my OLD rotors
That brings me to today. A few weeks ago, thanks to my buddy Justin, he and I were able to install a new set of Centric Premium blank rotors, new replacement set of Techna-Fit brake lines, and completely flushed my brake system with ATE Super Blue. I reused the CL RC5+ pads that I have been using. Also, my rear rotors were left on since they look fine and the rears doesn’t take the abuse the front rotors do.
Now, I haven’t been able to bed the pads to the rotors since I don’t want to risk that kind of attention on the roads in my area, but after reading the Essex Parts site again, particularly regarding how sintered pads don’t have to be bedded, I figured that I would be fine just driving them normally. It took about 2 weeks, but the cross hatching is finally worn away on the rotors, and the face has been completely covered/scrubbed. However, what I do notice is that there are some of these signs of spots starting to form. I have a feeling that what I’m seeing right now might be some of the color change associated with a sintered pad when they get some heat in them. I know that when these pads get some decent heat in them, they change the color of the rotors to a more gray/blue color, but after a day or two of driving, the nature of the pad when it’s cool makes them more abrasive and they “scrub” the surface clean back to the shiny silver we’re used to. Maybe it’s just the results of getting the pads warmed up a bit from normal stops at higher speeds.
For the record, since the new rotors have been installed, I have not bedded them or given my brakes a consistent work out at all. Also, I have not parked the car after doing any kind of aggressive braking. The few times I’ve used the brakes aggressively with any considerable torque has been to slow down after accelerating off an on-ramp to about 100mph and getting myself back down to 60mph. That’s it. That’s only happened maybe twice or three times since I’ve installed the rotors, and each time I was easily on the highway for 30 minutes following the use of the brakes. Otherwise it’s been completely normal daily driving.
Any ideas???
Thanks!
-Jalal
Below are just photos I took when I lubed the rear of the pads; showing the thickness of the pads; and showing the new rotor installed.
This is my NEW and current rotor
As some of you might recall, I posted a review thread of my Carbone Lorraine RC5+ brake pads. At the time, before the CL’s were put on, I was running GiroDisc Bailout rotors and their Magic pads which I hated. I was experiencing the brake shudder otherwise known as pad deposits or warped rotors. I knew I wanted to upgrade my pads since the Magic pads did jack **** for stopping power, and so knowing that the CL’s were sintered I figured I’d give them a chance to see if they could “scrub” my rotors clean of whatever deposits were on the rotor. To no avail, they still shuddered and I was left dealing with it until I could pick up a replacement set of front rotors.
Now, ever since I installed the CL RC5+, I noticed that my rotors began to develop these circular heat spots. I chalked that up to the pad deposits or heat spots and thought a new set would simple solve the issue. I didn’t actually know if the spots were actually a cause for concern because my rotors already were shot so I didn’t know if they contributed to anything negative other than looking odd.
Have any of you ever seen this before??? These are my OLD rotors
That brings me to today. A few weeks ago, thanks to my buddy Justin, he and I were able to install a new set of Centric Premium blank rotors, new replacement set of Techna-Fit brake lines, and completely flushed my brake system with ATE Super Blue. I reused the CL RC5+ pads that I have been using. Also, my rear rotors were left on since they look fine and the rears doesn’t take the abuse the front rotors do.
Now, I haven’t been able to bed the pads to the rotors since I don’t want to risk that kind of attention on the roads in my area, but after reading the Essex Parts site again, particularly regarding how sintered pads don’t have to be bedded, I figured that I would be fine just driving them normally. It took about 2 weeks, but the cross hatching is finally worn away on the rotors, and the face has been completely covered/scrubbed. However, what I do notice is that there are some of these signs of spots starting to form. I have a feeling that what I’m seeing right now might be some of the color change associated with a sintered pad when they get some heat in them. I know that when these pads get some decent heat in them, they change the color of the rotors to a more gray/blue color, but after a day or two of driving, the nature of the pad when it’s cool makes them more abrasive and they “scrub” the surface clean back to the shiny silver we’re used to. Maybe it’s just the results of getting the pads warmed up a bit from normal stops at higher speeds.
For the record, since the new rotors have been installed, I have not bedded them or given my brakes a consistent work out at all. Also, I have not parked the car after doing any kind of aggressive braking. The few times I’ve used the brakes aggressively with any considerable torque has been to slow down after accelerating off an on-ramp to about 100mph and getting myself back down to 60mph. That’s it. That’s only happened maybe twice or three times since I’ve installed the rotors, and each time I was easily on the highway for 30 minutes following the use of the brakes. Otherwise it’s been completely normal daily driving.
Any ideas???
Thanks!
-Jalal
Below are just photos I took when I lubed the rear of the pads; showing the thickness of the pads; and showing the new rotor installed.
This is my NEW and current rotor
Last edited by MJ23FE; Feb 23, 2012 at 11:47 AM.
#4
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Did you sand the pads before installing them on the new rotors? You have have picked up some stuff from the old rotors in thos pads and transfered it to the new rotors. All in the same spot on the rotor spaced apart like that is odd. Do some more driving and report back I guess for now.
#5
Did you sand the pads before installing them on the new rotors? You have have picked up some stuff from the old rotors in thos pads and transfered it to the new rotors. All in the same spot on the rotor spaced apart like that is odd. Do some more driving and report back I guess for now.
I wanted to scrub the pads a bit to clean them up, but didn't remember. BLAH!
I had my CL pads on the old rotors for ~17k miles, and they are the only pads that have seen these new ones.
Do you guys think I'll be alright?
-Jalal
#7
I just think it's weird that no one has seen this before. I thought they were simply heat spots, but who knows. It definitely does look like they follow a pattern since they larger spots seem evenly spaced. I didn't think twice about that before.
-Jalal
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#9
My new rotors are Centric Premium blanks pictured at the bottom of my first post. I'll try to get a photo showing what my NEW rotors look like. They are not spotted yet from what I can tell, but I will be keeping an eye on them.
I do plan on bedding my rotors at some point when I feel comfortable doing so on the public roads around me. I've had too many run in's with the local po-po and don't feel like having another one.
-Jalal
Last edited by MJ23FE; Feb 16, 2012 at 01:22 PM.
#10
Could be heat stress concentrations from the expanding and contracting steel. If there is a post under those spots for connecting the pieces of the rotor, that part of the rotor may be restricted from expanding with thermal loading, therefore when the rotor cools there is a residual stress in that region. It could also be that the extra material due to the post is helping to diffuse the heat in that spot, so it is not heating up as much. Either way, the local material properties will likely be different than the rest of the rotor if there is in fact material under those spots.
#11
Could be heat stress concentrations from the expanding and contracting steel. If there is a post under those spots for connecting the pieces of the rotor, that part of the rotor may be restricted from expanding with thermal loading, therefore when the rotor cools there is a residual stress in that region. It could also be that the extra material due to the post is helping to diffuse the heat in that spot, so it is not heating up as much. Either way, the local material properties will likely be different than the rest of the rotor if there is in fact material under those spots.
It's just odd that no one else has ever seen something like this before. I've asked a whole bunch of friends personally and none have ever experienced or seen this.
Weird.
-Jalal
#14
UPDATE
1,452 miles have been put on my new rotors, but I still have not been able to bed them. They have not been abused. They have not been heated up quickly and allowed to sit. Normal everyday use.
Over the past few days, I've noticed a slight shudder under light to moderate braking pressure. At around 75% pressure, the shudder goes away. I feel the shudder applying the brakes to slowly reduce speed on the highway, but not much below 40mph.
I changed my oil today and was able to get the brakes under some good lighting and this is what I found.
THE SPOTS ARE BACK!!! Currently their location is limited to only the outer edge of both front rotors.
WTF!?!?!?!?!?!
WHYYYYYYYYYYYYYYYYYYYY?!?!?!
I'll be contacting Jeff Ritter over at Essex Parts to ask him why he thinks this could be happening. At this point, the only idea have is that it's the pads which are causing this. But I have no idea why! Ugh. I just want pads that'll stop the crap out of my car on the street, regardless of speed, without any issues at all.
I know I need to bed them, but I really don't think that's going to help with my issue.
Thoughts, ideas???
-Jalal
1,452 miles have been put on my new rotors, but I still have not been able to bed them. They have not been abused. They have not been heated up quickly and allowed to sit. Normal everyday use.
Over the past few days, I've noticed a slight shudder under light to moderate braking pressure. At around 75% pressure, the shudder goes away. I feel the shudder applying the brakes to slowly reduce speed on the highway, but not much below 40mph.
I changed my oil today and was able to get the brakes under some good lighting and this is what I found.
THE SPOTS ARE BACK!!! Currently their location is limited to only the outer edge of both front rotors.
WTF!?!?!?!?!?!
WHYYYYYYYYYYYYYYYYYYYY?!?!?!
I'll be contacting Jeff Ritter over at Essex Parts to ask him why he thinks this could be happening. At this point, the only idea have is that it's the pads which are causing this. But I have no idea why! Ugh. I just want pads that'll stop the crap out of my car on the street, regardless of speed, without any issues at all.
I know I need to bed them, but I really don't think that's going to help with my issue.
Thoughts, ideas???
-Jalal