Rusty Rear Discs on 55 AMG - Mercedes Benz SLK Forum

Tires, Wheels, Brakes & Suspension Discussion and information regarding tires, wheels, brakes and suspension.

 5Likes
  • 2 Post By HarryH
  • 2 Post By frogfoot
  • 1 Post By DAVIETHESCAFF
 
LinkBack Thread Tools
#1 Old 07-04-2016
Registered Users
 
Join Date: Jun 2015
Location: Essex, England
Vehicle: SLK55 AMG 2005
Other Toys: GT40 Replica
Posts: 39
Country:
Chats: 0
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
Thanks: 13
Thanked 0 Times in 0 Posts
(Thread Starter)
Rusty Rear Discs on 55 AMG

I recently posted a Thread covering how I changed my rear Brake Discs.

I thought I would post this follow up thread as I wondered if other owners had found their Discs to be in the same condition as I did.

The reason I changed them was because, some time ago, when the car had been in for a Service, the front Discs were reported as having 30% wear but the note for the rear Discs just said “Corroded%.” with an Advisory Note saying “Requires rear discs/pads”. The easily visible, outer faces of the Discs didn’t show any corrosion but to enable me to check the inner face I removed a rear wheel and the pads. It was then possible to get a limited view of the inner face of the Disc. There did appear to be ridges on this face but with only the poor view available I couldn’t see any corrosion. However I set about researching what Discs and pads to buy. I settled on a pair of Original M-B Discs and pad pins (£495 inc. VAT) but bought my set of Pagid pads from Eurospares (£38-50 compared to M-B Pads at £128-40)

For various reasons, principally the fact that the brakes gave no sign of having any problem stopping the car, it was some months before I had time to begin the Disc change. When I finally got them off I was shocked at the condition of the hidden faces of each Disc.

As the Back Plate shields any clear view of the inner face of the disc it wasn’t until I got each of them off that I could have a good look at them. What surprised me was that I didn’t just find wear ridges but that, when I had removed both Discs, their inner and outer faces had an identical problem.

The outer faces were both worn smoothly but the outer half of the inner faces were both covered in in a layer of Brake Pad material.

The first photo I have included shows one of the outer, easily visible, faces. As can be seen these gave no hint of a problem.

The next photo shows the inner face of a Disc, with its covering of pad material.

The third photo shows a pair of Pads from one Disc. The Pad on the left shows where the Pad material has been stripped from it compared with the smoothly worn Pad on the right, which was in contact with the outer face of the Disc.

The final photo shows a closeup of the inner face of one of the Discs after I had picked off a small area of pad material . This could be done with a finger nail as it wasn’t firmly adhering to the rust pitted surface of the Disc.

A few other facts before I finish which may be helpful to anyone who could shed some light on what has caused this situation to have happened:

This layer of Pad material has a max thickness of only about a third of a mm.
The smoothish surface of the Pad material layer brought its level to that of the metal Disc.
The width of both Discs, between inner and outer faces is approx. 25mm. Well within normal wear limits.
Attached Images
File Type: jpg DSC06091.JPG (49.0 KB, 5 views)
File Type: jpg DSC06074.JPG (73.8 KB, 7 views)
File Type: jpg DSC06090.JPG (49.2 KB, 5 views)
File Type: jpg DSC06089.JPG (50.5 KB, 7 views)
jbanks15 and Avel Du like this.
HarryH is offline  
Sponsored Links
Advertisement
 
#2 Old 07-04-2016
Long Time Member

 
frogfoot's Avatar
 
Join Date: Sep 2009
Vehicle: 2005 slk
Posts: 3,598
Country:
Chats: 1
Mentioned: 159 Post(s)
Tagged: 1 Thread(s)
Quoted: 337 Post(s)
Thanks: 1,768
Thanked 913 Times in 455 Posts
Garage
Quote:
Originally Posted by HarryH View Post
I recently posted a Thread covering how I changed my rear Brake Discs.

I thought I would post this follow up thread as I wondered if other owners had found their Discs to be in the same condition as I did.

The reason I changed them was because, some time ago, when the car had been in for a Service, the front Discs were reported as having 30% wear but the note for the rear Discs just said “Corroded%.” with an Advisory Note saying “Requires rear discs/pads”. The easily visible, outer faces of the Discs didn’t show any corrosion but to enable me to check the inner face I removed a rear wheel and the pads. It was then possible to get a limited view of the inner face of the Disc. There did appear to be ridges on this face but with only the poor view available I couldn’t see any corrosion. However I set about researching what Discs and pads to buy. I settled on a pair of Original M-B Discs and pad pins (£495 inc. VAT) but bought my set of Pagid pads from Eurospares (£38-50 compared to M-B Pads at £128-40)

For various reasons, principally the fact that the brakes gave no sign of having any problem stopping the car, it was some months before I had time to begin the Disc change. When I finally got them off I was shocked at the condition of the hidden faces of each Disc.

As the Back Plate shields any clear view of the inner face of the disc it wasn’t until I got each of them off that I could have a good look at them. What surprised me was that I didn’t just find wear ridges but that, when I had removed both Discs, their inner and outer faces had an identical problem.

The outer faces were both worn smoothly but the outer half of the inner faces were both covered in in a layer of Brake Pad material.

The first photo I have included shows one of the outer, easily visible, faces. As can be seen these gave no hint of a problem.

The next photo shows the inner face of a Disc, with its covering of pad material.

The third photo shows a pair of Pads from one Disc. The Pad on the left shows where the Pad material has been stripped from it compared with the smoothly worn Pad on the right, which was in contact with the outer face of the Disc.

The final photo shows a closeup of the inner face of one of the Discs after I had picked off a small area of pad material . This could be done with a finger nail as it wasn’t firmly adhering to the rust pitted surface of the Disc.

A few other facts before I finish which may be helpful to anyone who could shed some light on what has caused this situation to have happened:

This layer of Pad material has a max thickness of only about a third of a mm.
The smoothish surface of the Pad material layer brought its level to that of the metal Disc.
The width of both Discs, between inner and outer faces is approx. 25mm. Well within normal wear limits.
condensation forms between the disc and back plate when the car is stood overnight causing surface rust . the front of the disc is not effected as air can flow around it unrestricted. also washing your wheels and then leaving the car stood till the next day or longer before you use it speeds up the rusting
DAVIETHESCAFF and Avel Du like this.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Designo 6speedMT 350........My weekend , Holiday Transport since 2008
frogfoot is offline  
The Following User Says Thank You to frogfoot For This Useful Post:
#3 Old 07-05-2016
AND MABEL

 
DAVIETHESCAFF's Avatar
 
Join Date: Feb 2013
Location: Barrhead
Vehicle: 2008 AMG 55
Other Toys: "Red Mist" 2004 Battistini Hardtail Chopper
Posts: 13,480
Country:
Chats: 0
Mentioned: 148 Post(s)
Tagged: 1 Thread(s)
Quoted: 592 Post(s)
Thanks: 3,032
Thanked 1,030 Times in 874 Posts
Garage
Leaving your car sat unused outside for even short lengths of time can cause the discs to rust. I have to leave mine for 2 - 3 weeks when I go off shore, allowing the rust to build up, and every car I've had has had shortened disc/pad life spans due to this.

On the bright side, the solution is to get out and drive it every day.
frogfoot likes this.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
.........Happiness is not getting what you want, it's wanting what you have.........Daviethescaff
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
DAVIETHESCAFF is offline  
Sponsored Links
Advertisement
 
Reply

  Lower Navigation
Go Back   Mercedes Benz SLK Forum > Technical Information > Tires, Wheels, Brakes & Suspension

Bookmarks

Quick Reply
Message:
Options
Upload your files to MEGAUPLOAD
Upload your images to ImageShack

Register Now



In order to be able to post messages on the Mercedes Benz SLK Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
Rear Brake Discs on 2005 SLK55 AMG Mark55 Tires, Wheels, Brakes & Suspension 9 05-05-2017 08:36 AM
Mercedes will task dealers to step it up for AMG Berliner Heckflosse Off Topic 0 10-12-2015 01:33 AM
Mercedes-AMG New Lifestyle Accessories Collection Is All About the GT Berliner Heckflosse Off Topic 1 03-27-2015 10:43 PM
AMG Private Lounge Gathering at Palm Beach International Raceway, FL, May 10, 2014 igormina AMGs 0 04-17-2014 04:52 PM
R172 AMG exhaust and rear diffusor babyvox_lover SLK Parts For Sale 0 05-28-2012 09:38 PM

Posting Rules  
You may post new threads
You may 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

 
For the best viewing experience please update your browser to Google Chrome
 

Clubs, Garage Plus vBulletin Plugins by Drive Thru Online, Inc.