Quick Question, Rear Brakes E350
 

I have just a bit over 100K and am doing the rear brakes for the first time.
This is my wife's daily driver.


Not looking for a performance upgrade, nor worried about non-normal or excessive wear.


So the question is do I really need to do the rotors.
I usually figure 2 sets of pads to each rotor assuming no problems, but that is on cars that get 40k to 80k miles per set of pads.
Can I use the same here even with the pads/rotors at over 100K?
They look good, no grooves, but definitely not as flat as new rotors.


Thoughts?

I'm preaching to the choir here N_Jay since I know you aren't a scrub but here are my thoughts:

As you know, rear brakes handle a lot less of the braking force than front brakes for most driving styles, if the rotors are not grooved or in bad condition you could probably get away with using them for another set of pads. If "flatness" is an issue or they are causing vibration, you always have the option to resurface, but this is likely a sign of rotor wear anyway and they should be replaced. Also, do you think the rotors are in good enough condition that they will perform optimally at 180k if they are showing signs of wear right now? Haven't seen the rotors so can't really answer that. I would also interpret any discoloration as a sign it's time to replace them.

The main thing is that rotors do have a braking surface on them that can get worn down. Usually this only happens when you fail to replace your brake pads on time, but it is something to consider.

I guess the final point to consider is that brakes are a safety item and the most important woman in your life (presumably :rolf:) is driving, and while rear rotors aren't as important a safety item as good tires and good front rotors, it could be argue that it shouldn't matter and to just get them done.

You could probably get aftermarket rotors cheaper than the OEM ones, check parts.com or contact R1Concepts.

Thanks.
guess I am looking for some experience with these cars.
Just looking at them I would have no problem leaving them on. But the 100k miles is what makes me wonder.
No groves, no discoloration, no vibration, all four pads worn even. They look like any good rotor after 1 set of pads.

You should be fine then, I was in the same boat when I did my first brake job at 110k, and while my front rotors were trashed, I could have safely left the rears on for another set of pads. The mechanic that did the installation concurred.

I normally wouldn't be so cheap, but the last couple of months have been tight and with winter coming, I was thinking changing pads in the cold garage is one thing but pulling the rotors would probably double or triple my "cold hands" time.


Darn GL need a B service and I can't put that off because I have 2000 miles trip for Thanksgiving.

Ahhh I see your dilemma, I am almost due for a B service on my E-Class but I'm hoping they remember I have a free B service lined up for me at MB of Littleton after they screwed up my car beyond belief after the last service A. We will see if they honor that, I will be surprised if they will.

Almost flew out to Littleton to look at a GL they had.
It was about 140K miles priced at about $20K
More miles than I was looking for but couldn't beat the price.
They ended up selling it before I set up the trip.

Oh really? Darn, if it's any consolation I've been fairly dissatisfied with them the last few times I've gone their either to their showroom or their repair center. When I asked to test drive a used W212 E550 they told me they don't do test drives and to get lost, I guess that's what you get for looking young. I wouldn't buy from them anyway, they're a bunch of pretentious a-holes most of the time when I go there, even though I fork over hard-earned cash like everyone else.

Keep this simple Measure the rotor thickness and use a dial indicator for run out. If less than .004 run out and you have the thickness within spec, they are in spec use the rotors. Why worry about performance upgrade on pads if OEM went 100000 miles why not just put on oem and not worry. My guess without seeing. New OEM pads and go another 100000.

Thanks for the vote of confidence.


Changing to Centric quiet ceramic, as they are a good price and I have had good luck from a noise, dust and performance standpoint.


Now, I just hope I get a decently warm day to change them.