SL55AMG successful DIY Front Brake disc and Pad replacement (incl. SBC)

John757

Active Member
Joined
Aug 7, 2010
Messages
632
Location
Surrey UK
Car
E350CDi Coupe AMG (2010) , G Wagen G280GE Short (1990), SL55 AMG (2003)
Yesterday after much prevaricating, I decided to replace the front discs and pads on my 2003 SL55AMG (73k miles). The reason for my reluctance was reading the many and varied suggestions here and on other forums on how to avoid having my fingers crushed by the SBC computer applying the brakes unexpectedly. To be honest I have changed brake discs and pads on most of the cars I have owned, including a C3 Corvette, Audi Quattro, E class Merc, BMWs etc etc, the SBC however and reading the warning posts did give me a few concerns about doing it myself.
I bought the car last July, and within a month bought all the necessary bits to replace the brakes and pads. A pair of new Genuine MB Discs, x8 new MB Brake pads, x4 new retaining pins and x4 new retaining spring clips, a new brake sensor wire, x2 new brake retaining screws, x4 new brake caliper to hub carrier bolts all from Mercedes Benz Parts, total cost £500. (Pics of part numbers in this thread)
So after much research.. I took the plunge.
My procedure is as followed and it worked as expected.
  • Open car,
  • open bonnet (hood)
  • removed jack from the boot.
  • lower both front windows
  • lock the car after first disabling the alarm motion sensor and tilt switch on the centre console.
  • place keys in a faraday pouch or tin somewhere where no-one will touch them.
  • wait 10 minutes.
  • jack the car using the supplied jack (after finding my trollyjack was too tall to go under the sill) Santa informed!
  • I used an axle stand under the jacking point at all times.
  • disconnect SBC plug under bonnet by pulling on the top locking tab until it ejects from its connector.
  • Either batteries were not disconnected
  • remove wheel
  • remove brake wear sensor from pad and unplug (only one is on right hand side RHD Vehicle)
  • drive out pad pins towards inner wing
  • undo two torx bolts holding pad retaining plate across back of caliper
  • remove x4 pads (per side) (I photographed them so they go back in the correct positions)
  • undo two 22mm caliper retaining bolts
  • use bugee cord to support caliper
  • remove torx screw holding on disc
  • clean all surfaces
  • at this point i removed the brake fluid cap
  • carefully by hand squeeze the brake pistons back into the caliper whilst monitoring the fluid level which will rise.
  • i had to suck out some fluid with a large brake bleeding syringe (available from internet) as the level rose
  • clean caliper
  • apply anti seize paste to hub and replace with new disc
  • attach hub with new torx retaining screw (30NM)
  • replace caliper with new bolts (blue locking compound is already applied to new bolts by MB)
  • torque bolts to 180NM
  • insert new pads starting at bottom, covering rear of pad retaining plate with copper grease (anti squeal)
  • clean and attached pad retaining bar with two torx screws one either end (i re used these)
  • insert pad retaining pins (new) from back of caliper as well as retaining clips (new) and tap in until seated home
  • ensure retaining clips sit in between the grooved channels of the pins and on the back of the pads
  • plug in new pad wear sensor
  • replace wheel and complete same for other side.
  • carefully reattach SBC computer plug and push down retaining tab on top until locked.
  • check brake fluid level
  • open car and start engine
  • As expected the dashboard flashed red with SBC warnings as the system took up the slack and adjusted the pads and I applied the brake pedal several times.
  • I also took the car out of park into neutral and released the handbrake to allow the car to settle on its springs, (from jacking it up)
  • after about a minute the brake warning lights all went out.
  • icarsoft MB11 V2 diagnostic computer attached and no faults were found- You cannot disable SBC with this unit on this SL55AMG (other models may be different) faults can be read and cleared if they occur.
  • Road test and recheck brake fluid level (DOT4+)
  • Allow brakes to bed in over a few days.
This method works well for me on this car. I this helps to reassure anyone that a competent home mechanic can replace the discs and pads without the need to have STAR.

I always strive whenever possible fit OEM parts to my cars..
The brake discs on an SL55AMG are a massive 360mm and drilled and vented and weigh about 30lbs each!

The old pads were about 60% worn and the old discs were most likely originals and had a lip and some light grooved wear.

Here are a few pics of this job.

New OEM Parts
20220517_105605.jpg 20220517_105619.jpg 20220517_105800.jpg 20220517_105843.jpg 20220517_111605.jpg 20220517_122736.jpg 20220517_130207.jpg 20220517_105713.jpg 20220517_105715.jpg 20220517_105800.jpg 20220517_105823.jpg 20220517_105838.jpg 20220517_105843.jpg

20220517_155735.jpg 20220517_155642.jpg 20220517_134544.jpg 20220517_133523_1.jpg

I may have the calipers repaint refurbished at some point, the pistons moved easily with no signs of seal
deteriation.. I did see that the front shock dust covers have split when dropped down fully on the jack. This car had refurbed front struts a few years ago.. so I am surprised to see that.
 

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Last edited:

chic0821

Active Member
Joined
Jul 20, 2016
Messages
721
Location
Scotland
Car
S63 AMG Coupe, Range Rover Sport, 992 Porsche Carrera 4S
Good job, well done. Great pictures, should help any novices who are reluctant to try it.👍
 

Lenny63

MB Enthusiast
Joined
Jul 6, 2012
Messages
1,352
Location
Belfast
Car
CLS 55 AMG | S211 E280 Cdi Sport
Fair play to you mate, great work. I'd never have the balls to tackle this myself as I know when my indie when to do my fronts on the CLS the pins were seized and he had to cut them out in sections and gently tap out the remainder....eek !
On my old E wagon, it has the Brembo brakes as it's a sport model and with similar pins as well ... they were of similar vein
 
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John757

John757

Active Member
Joined
Aug 7, 2010
Messages
632
Location
Surrey UK
Car
E350CDi Coupe AMG (2010) , G Wagen G280GE Short (1990), SL55 AMG (2003)
Thanks for the comments... the retaining pins came straight out..
I noticed an updated design of the retaining spring clips also compared to the old ones..
brakes bedding in nicely.. big improvement on brake feel and bite... smooth and quiet..
the old brakes felt a little wooden... underwhelming..

these... feel like AMG brakes!
Screenshot_20220518-125302_Gallery.jpg
 

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