GS - 4th Gen (2013-2020) Discussion about the 2013 and up GS models

Brown marks on new rotor.

Thread Tools
 
Search this Thread
 
Old 09-19-15, 10:05 PM
  #1  
richard203
Racer
Thread Starter
iTrader: (1)
 
richard203's Avatar
 
Join Date: Nov 2008
Location: SF
Posts: 1,478
Likes: 0
Received 118 Likes on 104 Posts
Default Brown marks on new rotor.

I just changed my pads and rotor and when I drive back home notice my passenger side have the brown mark on the rotor. My driver side doesn't have that. Is the passenger side a defective rotor or its normal on new two piece rotor? I never have brown marks on bew rotor before. Any help?

Old 09-20-15, 08:26 AM
  #2  
DaGr8GatsB
Driver School Candidate
 
DaGr8GatsB's Avatar
 
Join Date: Aug 2015
Location: California
Posts: 15
Likes: 0
Received 0 Likes on 0 Posts
Default

I think you might have glazed your rotors. Did you brake them in correctly? Smooth and slow stops for at least the first 100 miles. Never do hard braking until they're fully bedded in.

You might have to get them resurfaced.
Old 09-20-15, 08:28 AM
  #3  
DaGr8GatsB
Driver School Candidate
 
DaGr8GatsB's Avatar
 
Join Date: Aug 2015
Location: California
Posts: 15
Likes: 0
Received 0 Likes on 0 Posts
Default

Or you can try sanding the rotor surfaces yoursellf but risk creating high and low spots if not done properly
Old 09-20-15, 08:47 AM
  #4  
Sevn86
Pole Position
 
Sevn86's Avatar
 
Join Date: Apr 2012
Location: Texas
Posts: 2,233
Received 83 Likes on 55 Posts
Default

Maybe something got lodged between the brake pad and rotor?
Old 09-20-15, 08:55 AM
  #5  
richard203
Racer
Thread Starter
iTrader: (1)
 
richard203's Avatar
 
Join Date: Nov 2008
Location: SF
Posts: 1,478
Likes: 0
Received 118 Likes on 104 Posts
Default

Wat is the brown stuff?
Old 09-20-15, 09:03 AM
  #6  
95bat
Racer
 
95bat's Avatar
 
Join Date: May 2012
Location: CA
Posts: 1,789
Received 1,211 Likes on 632 Posts
Default

Were your rotors coated? Many of them have a coating that rubs off during the first few hundred miles.

Or did that wheel get wet? Could just be a little surface rust.
Old 09-21-15, 11:21 AM
  #7  
cquence
Former Sponsor
 
cquence's Avatar
 
Join Date: May 2015
Location: California
Posts: 151
Likes: 0
Received 1 Like on 1 Post
Default

Echoing what DaGr8GatsB suggested; it looks like glaze and so make sure that you don't brake hard during the first 100-500 brake miles. Follow the break-in procedure and all the way through the duration as specified (100-500 brake miles) without any hard braking. Do not sand the rotors, a lathe machine cuts/turns the rotors in a manner that is more precise than sanding.
There is a small chance that there is some coating on the rotors, sometimes it's cosmoline to protect the rotors from rusting when sitting on the shelves or other treatments. It'll eventually wear off within 100 brake miles.
Feel the surface and see if there is any unevenness. If there are none, go through the break-in procedure, you can find this online with varying degree of speed and duration, and then examine the rotors again. Report back with anything usual. Hope this helps.
Old 09-21-15, 12:26 PM
  #8  
islandbeef
Racer
 
islandbeef's Avatar
 
Join Date: Feb 2014
Location: SoCal 858
Posts: 1,679
Received 62 Likes on 38 Posts
Default

After a downpour of rain, I noticed my rotors had rust marks shaped like beads of water. They properly disappeared after braking.
Old 09-21-15, 08:22 PM
  #9  
richard203
Racer
Thread Starter
iTrader: (1)
 
richard203's Avatar
 
Join Date: Nov 2008
Location: SF
Posts: 1,478
Likes: 0
Received 118 Likes on 104 Posts
Default

K just for a follow up my front rotor is now back to silver color but the rear brake is brownish color any1 can confirm their rear rotor is like this? The rear brake didn't get changed since it still got meat in it.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
xaker777
IS F (2008-2014)
25
06-16-18 08:10 AM
VIPNiSS
GS - 3rd Gen (2006-2011)
10
09-13-10 11:05 AM
LexiGx470
GX - 1st Gen (2004-2009)
3
01-16-08 06:40 AM
chanman
Suspension and Brakes
6
09-21-01 05:48 PM



Quick Reply: Brown marks on new rotor.



All times are GMT -7. The time now is 12:33 AM.