ambit

I looked at the service history for the car, these are original rotors. I've put almost 40,000mi on them since June 2011. Car was pretty much babied before me.

Battery on my caliper died, but its still a bit over 30mm

I wasn't exactly square on, it might be right around 29-31mm?

I found MB P/N A 1714210112 on the driver-side rotor. Should be ordering new ones tomorrow.

cm60k

Thankss for sharing that....

ZAYED,,

cm60k

Are you going to order same Rotors or 1 piece Rotors.....??

ZAYED,,

ambit

New rotors are in!
They don't look any thicker than the used ones


22.8lbs/each!

Almost 13.5"

$1100 of sadness

cm60k

Excellent...,,

what gonna do with oldies...??

ZAYED,,

waveterrorist

You will likely never mount up another pair.

5k miles since I paid big $$ to have mine turned and they are doing their job as designed...

Critter

@ambit, remove the rotor and clean up the back side of the rotor with emery cloth, what you are experiencing is the rust from where the pads sat for a while, in the second video when you here the noise it is on the back with the pad in is the same place when you see the front rust spot go by. Rust on the surface makes the rotor thicker. For some reason most rotors will look worse on the back side, but this is your problem. The pads are not aggressive enough to remove the rust surface on the face, if you had say ceramic or pads with a lot of steel particles in them the rotor would clean off.
While you have the pads out scuff them across some emery cloth also to remove the rust imbedded in the surface of the pad.
Again soft pads will not clean off rust on a rotor.
Good Luck, do not buy rotors just yet, you will be surprised at the surface on the back side of the rotor.

Critter

Too Late I guess, anyways do not use the old pads on the new rotor, might as well start out fresh.
Your old rotors did not even show a lip, they could not have been that used.

ambit

So the new rotors fixed about 90% of the problem.
cm60k: Not sure what to do with the old ones, they're too friggen heavy to make a clock or something out of.
I did notice the old pads were not making the best contact with the new rotors so I ordered new pads too $216.95 MB P/N 005-420-39-20 from getmercedesparts.com (same place I got the rotors from)

Back side of the rotor with old pads since Critter asked:

The inside (back?) pads were making better contact than the outers on both sides.

Anyway, new pads came in today, here they are on the old rotors:


They're about twice as thick as the old pads.
I moved the wear sensor over and fought with the pistons trying to get all 3/per side moved back at the same time. Ended up over-flowing from brake fluid from the reservoir but got it all done.

Sadly, there still a tiny bit of 'wobble' under heavy braking above 70mph. But under 40mph (which is 90% of my driving these days) it is back to normal.
And you can see after just 20 miles the whole disk surface is being swept again:

cm60k

Good job..,

with new pads, Rotor surface reflects everything FINE.....

ZAYED,,

dave2001auto

What are the thickness of the new vs. old rotor and pads?

The price of the new rotors would tempt me to resurface them if well within the min thickness. Ask a rotor shop if they have the ability to stress releive the warped rotors.

Critter

Just to clarify could you show a picture of the whole backside of the rotor, you probably have seen that where the rear pad was sitting the surface is oxidized making it thicker and also the reason the rotor would stop in the is area.
As you have stated this new rotor setup did not actually resolve your issue, now look at the rear rotors and you will see the same start stop issue as with the front.
In the picture these rotors have minimal surface wear

waveterrorist

is that replacing the rear rotors/pads only costs about 1/2 the front~

dave2001auto

For over $1000 for the front pair, I am surprised that your brake shop or autoparts store didn't recommend that they be resurfaced the rotor (light grinding or sanding) to remove the glazing and rust. Make sure your pins are clean to allow the calipers to float properly. Some also try to remove glazing by rubbing the pads on a flat concrete floor. I use new pads.

Critter

unpainted concrete floor, but yes you are correct. Crocus cloth/pads works well on surface rust on rotors as they do not remove the steel surface but only the rust and glaze.

ambit

dave2001auto:
I'm going to pull the front pads tonight and put some anti-squeek on them, I'll measure.

I took the car to Belle Tire, explained how much the new ones would be and asked if anything could be done. They said they were too thin

Critter:
The heatshield/splash guard covers most of the back of the new mounted rotor. I'd have to take it all apart again for a better pic, sorry.
I'll get some better pics of the old rotors too.
I haven't even looked at the back wheels yet to see if they're having the same issue.

Edit:
new pics!
Sexy fully swept rotor:


New vs old pad pics for dave2001




Goddamn squeaking was driving me nuts

dave2001auto

Yes of course using non-painted concrete floor as the pad abrasive. By eye balling, the pads look like 3mm for the old pad and 9mm for the new pad. Old pads are almost finished. The metal plate does not count for the useful pad life.

From the old rotor pictures, it was about 32mm thick and about 34mm for the new rotor. Am I eye balling correctly? What the min. thickness which should be molded or stamped on the old rotor?

Moedy

Wow, I was getting this odd noise from the front of my car and was thinking it was the cooling fan. I finally pinpointed it to be the rotor. It does it after the car sits for a day and goes away after the first time I hit the brakes. My car is also a 2005 with roughly the same mileage and it's the front passenger rotor too!!! What a coincidence!!

Critter

If you wash the car or it sits in the rain chances are that rust will start to form on the rotor, this will create noise when applying the brakes for the first or second time but will be wiped clean from the friction created by the pads. If the car sits for a long time the surface of the rotor under the pad will be more or less oxidized depending if the car was stored inside or left to the elements. In this scenario the brakes could pulsate and grab until the total rotor surface is again cleaned by the pad. Excessive rusting will not be removed by the above methods but will contaminate the pad surface and cause other issues. Excess rust should be removed with crocus cloth or sandpaper with attention to the area of the rotor where the brake pad was positioned.

Inno68

I had a similar instance happen to be me but with a different model car , I was over tightening the wheel with a Breaker Bar , When I replaced the Rotors I had the same thing happening . When I purchased a torque tool , I didn't have rotors warping on me anymore.

waveterrorist

i am not going to say they can't be over-torqued but i think it is very safe to say they are far less impacted

ambit

I had the tires swapped at Firestone back before Thanksgiving (before the car sat) and they had them torqued down correctly.

New discs have been great. Couple thousand miles on them and 1 track day. No issues front or rear.

But now the A/C is hissing