Today I replaced the rear rotors and pads on my E500. I didn't bother to do a HOW-TO, because the procedure is pretty much like changing the front brakes and rotors, of which there IS a
HOW-TO here on the forum.
I had in recent weeks and trips, noticed that the brake warning light was flickering, which is the classic sign of brake pad sensors indicating brake pad wear.
Looking through my maintenance notes, I had the following notation from January 24, 2015, when the car had 129K miles on it:
Rear brake pads getting low, perhaps 20-25% left. Rotor slight lip but OK.
The car currently has 251,400 miles on it, so that last 20-25% of the pads lasted a good 20K miles! The rotors didn't seem discernably more worn than they were in 2015 -- still had a modest lip. The pads were MB pads. I replaced them with Akebono Euro 495 pads, which I had had in my parts stock since 2013. I replaced the front pads with Akebono Euros more than a decade ago, and was just keeping those rear pads for a day like today.
I have no record, in my more than 22 years of ownership, of ever replacing the rear pads and rotors. Evidently I had previously removed the rear rotors and used anti-seize paste on them as a practive measure, becuase both rotors came off like butter, and had clear evidence of silver anti-seize paste on the faces of the hubs. So this made the job IMMENSELY more enjoyable, because I didn't even have to use a hammer to bang on the rotors to coax them off the hubs. They literally came off by wiggling them with my hands.
Here are some photos and close-ups of the four rear brake pads, along with the sensors. As you can see, the sensors were all worn, and one sensor had even come out of its hole!!
I was able to source a proper set of 500E/E500-specific rear rotors, which are officially NLA from MB and aftermarket sources. Some years back, MB superseded the E500E rear rotors to the 400E rotor, which is the same diameter, but the 400E/E420 rotor is 2mm shorter than the E500E rotor in the "hat" portion. This means that the wheel of the E500E, using these superseded 400E rotors, would be set into the wheel well by 2mm each side. Probably not discernable to most, but.....
You can find NOS E500E rotors, but they are around 50-100% more than the 400E rotors available. But, it's nice to have the correct part on the car. For most owners, this is probably a once in an ownership change.
Here is the label from the box of the NOS set of rotors I got, which were made in Germany and branded Textar, one of the MB brake pad OEMs and a quality brand. The rotors came unpainted (bare metal), so I -- at the
@gsxr's recommendation -- bought a can of gray zinc chromate paint and gave both rotors a couple of modest coats of paint. The paint is the same exact stuff that the factory MB rotors ship with, and the cost of the can of paint was under $12.00 at Home Depot. It dried quickly in the fall sun. I used about 2/3 of the can.
Anyway, a quick test drive wore the paint off of the pad sections, and the brakes work great. I need to bleed them (replace the fluid), and also need to properly bed in the pads, but this will come with some additional driving.