Brake Disc Replacement
MBWorld Fanatic!
Joined: Sep 2005
Posts: 6,191
Likes: 242
From: Albuquerque
'10 CL550, '12 GL550
Normally the rotors (discs) are replaced at the same time as the pads. The warning, however, just indicates worn pads. There is no warning for rotors, just visual inspection. It's pretty easy, too, to visually inspect the pads. The friction material when new was pretty thick, about 1/2 inch or a little more.
With cool components, use fingers to check for lip at edge of rotor. This indicates how much metal has worn off the rotor. New rotors have no lip. The same lip will exist on the other side that you cannot access to feel. Any lip at all will probably indicate at least 1 mm wear. The wear limit is 2 mm ... remember the other side. There is no refinishing ... the material is gone.
New pads can be installed with old rotors. However, new rotors must be installed with new pads ... so best to do it all. Note: if warning light happens, it means you need new wear sensors, too. When replacing rotors, the caliper carriers are removed from the hub to gain access. New bolts are required when remounting the carriers ... bolts not reusable.
With cool components, use fingers to check for lip at edge of rotor. This indicates how much metal has worn off the rotor. New rotors have no lip. The same lip will exist on the other side that you cannot access to feel. Any lip at all will probably indicate at least 1 mm wear. The wear limit is 2 mm ... remember the other side. There is no refinishing ... the material is gone.
New pads can be installed with old rotors. However, new rotors must be installed with new pads ... so best to do it all. Note: if warning light happens, it means you need new wear sensors, too. When replacing rotors, the caliper carriers are removed from the hub to gain access. New bolts are required when remounting the carriers ... bolts not reusable.
Thread Starter
Senior Member
Joined: Aug 2017
Posts: 396
Likes: 11
From: Ontario, Canada
2006 ML500, 2008 ML350
Thanks for the advice. Would you say the caliper bushings need to be replaced too?
I've had this car since 2010 and never had to replace any brake part during this time while braking power was perfect all the time. I just changed the brake fluid last year. Ain't it amazing?
I've had this car since 2010 and never had to replace any brake part during this time while braking power was perfect all the time. I just changed the brake fluid last year. Ain't it amazing?
MBWorld Fanatic!
Joined: Oct 2011
Posts: 7,107
Likes: 765
From: Bronx, N.Y.
2002 ML 320 & 2006 ML500
Thread Starter
Senior Member
Joined: Aug 2017
Posts: 396
Likes: 11
From: Ontario, Canada
2006 ML500, 2008 ML350
Trending Topics
MBWorld Fanatic!
Joined: Oct 2011
Posts: 7,107
Likes: 765
From: Bronx, N.Y.
2002 ML 320 & 2006 ML500
MB World Stories
The Best of Mercedes & AMG
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)
Verdad Gallardo
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
MBWorld Fanatic!
Joined: Oct 2011
Posts: 7,107
Likes: 765
From: Bronx, N.Y.
2002 ML 320 & 2006 ML500
