Brake Pad replacement - True or false question
 

I am getting the brake wear indicator on my dash of my 2007 SL550. I scheduled an appointment with a very reputable independent mechanic to get my pads replaced and he said you always need to change out the rotors and wear sensors when you do the pads. My car has 24,600 miles on it.

So true of false, you always change the rotors with the pads?

Ahh no....im no mechanic but never in my history have I ever heard of doing that especially at such low miles. Your rotors should last a lot longer than your pads.

Dealers and some
 

shops would follow the book and r/r rotors. Even if they were perfectly smooth just to avoid any issues with call backs if noise or other issues cropped up
in addition to the profit motive of course:)
So if they are smooth and no ridges you can get another use out of the fronts and most people several uses out of the rears.
Since mb rotors don't have much in the way of excess they can't be resurfaced
That is why they need to be replaced if not perfect.
And yes the wear sensors need to be replaced but they are only a few bucks each
Why not diy?

The bigger question is - why do you need to replace the pads after 24K miles? Did you track the car? If you didn't, take the wheels off and check the pads with a flashlight - maybe it's the sensor, not the pads?

As for your question - the rotors are designed to last as long as the pads. True, you can resurface them (a must with every set of new pads, not because of grooves, but because they must be machined back to parallel as due to caliper flex rotors never wear parallel) but after resurfacing the rotors they wont last another pad life duration, i.e. the rotors could very well reach min. thickness after the 2nd pads are only 50% used.
Don't skimp on your brakes, your life could someday depend on them working to their max.....

not rotors, but if you have the brake wear sensor message on the dash that means the connection in the sensor is broken due to a worn out pad. so yes sensor has to be repalced. they are less than 10 dollars. 2 sensors for each side on the front and one sensor on for the rear.

Thanks for the responses guys. I am not really concerned about the cost as much as just trying to make sure it's an honest answer. I have had a set of Akebano pads sitting on my garage shelf waiting to replace. I am hoping it cuts down on brake dust.

As for DIY - "don't skimp on your brakes, someday your life may depend on them!" - nuf said

rotors
 

AMG advises to replace rotors with brakes on AMG cars.....called Germany to verify.......don't know about non-AMG, but if the rotors are within spec they should be okay to reuse if smooth....

You only need to replace them if you get vibration when you brake or the surface is uneven. MB recommends they be replaced every time which is why brake jobs at the dealer cost more college tuitions

For front brakes
 

24k miles is actually pretty good .
Not track related wear at all.
And no you CAN'T RESURFACE THEM.
As to The DIY suggestion it ain't rocket science That's why brake jobs at the dealer are performed by kids just out of training class.
Frnt brakes Sl 550 takes longer to jack the car up on stands then it does to pop out the pads and replace them and the sensors.
Follow the Akebono bedding in procedure to the letter and be sure to use the paste and you will love the lack of dust.:y
Been doing my brakes on Benz for a bit over 40 years and they are as simple now as they were then and I'm still here.
Good place to start your Diy that way you won't be in shock next year when your SL is 5 years old and he hits you for A grand to replace $100 worth of off the shelf spark plugs.
Like i said most people get 2 uses out of the fronts(Full pad uses:))

I replaced my pads around 27K at the dealership and was told rotors can be done later. Previous owner was an older gentlemen and I never tracked the car.

pfft... sorry. do you always wear 5-point harnesses in your cars too?

the book does call for always doing rotors and pads, but in reality when rotors reach minimal useful thickness they will warp and start to "heartbeat" in the pedal when breaking from higher speeds. that is your clue that they need to be replaced.

replace pads only until the rotors warp. then replace rotors as needed.

your mileage will vary, but those are just my 2 cheap cents

alex

Dealer replaced just the pads mine lasted 40k. Front and rear. Rotors were still in spec.

my rotors are warped in the front and I will be needing to replace them, but for the most part they should be able to be reused, anyone need a set of good condition factory sl600 pads? I am thinking the akebono route is a must with my wheels