Parts Catalog Accessories Catalog Tech Info Tech Forums
  Search our site:    
 Cart  | Project List | Order Status | Help    

Go Back   PeachParts Mercedes ShopForum > Technical Information and Support > Tech Help

LinkBack Thread Tools Display Modes
Old 03-19-2003, 01:51 PM
Coming back from burnout
Join Date: Jun 1999
Location: in the Pacific Northwest
Posts: 2,274
Brown discoloration on Brake Disk Rotor 83 240D

Now that the days are getting longer and I can do critical service work without a flashlight in 9 degree weather, I can see a brown ring on my brake rotor. The caliper failed on this side.
I dont think my failed brake caliper siezed on the rotor and I dont think my brakes were stuck in a locked braking position and the brakes were not literally smoking.
I think the brake piston got stuck in the retracted postion and ceased to function and provide braking pressure.

Nevertheless my Rotor has a brown ring on it. Should this be indicative of a failed rotor and thermal discoloration? Or is the brown ring a sign of some less severe condition. I always though thermal discoloration of overheated high carbon steel was Blue and not brown...

Brown discoloration on Brake Disk Rotor 83 240D
Reply With Quote
Old 03-19-2003, 02:16 PM
Registered User
Join Date: Jul 2001
Location: SoCal
Posts: 1,303
See if it comes off with some steel wool - e.g. organic contaminant or rust.

Reply With Quote
Old 03-19-2003, 08:08 PM
I told you so!
Join Date: Jun 2002
Location: Motor City, MI
Posts: 2,743
Discoloration from heat is anywhere from straw to black. The stages are: light straw-straw-purple-blue-black. Brown is hydrated iron oxide. I think you're looking at rust.

Does the car sit idle for long periods? Brakes suffer first on a car that sits unused. If the shiny metal doesn't come back on the rotor surfaces after running it for a couple weeks, then check into the possibility you may have a seized caliper.
95 E320 Cabriolet, 131K
Reply With Quote
Old 03-19-2003, 10:02 PM
Registered User
Join Date: Feb 2003
Location: Ontario, Canada
Posts: 3,160
Wash your car & then park it right away.
Look at the rotors the next morning, and you will see the same brown ring ( rust ).
Not much to be concerned about, as you will scrub it off with your first brake application.
2007 C 230 Sport.
Reply With Quote


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -4. The time now is 12:43 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2011 Pelican Parts - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page