killatee18

Hi All, looks like my rear pads need to be replaced. Also noticed that rotor have some bumpy ridges on them. I was wondering if any of you guys ever resurfaced your rotors or did you just replace them completely??? Thanks!

PS: I have a 2007 E350 sport without 4matic.

HE22WA

Hi, I got mine resurfaced or as we call them here 'machined' for a couple of hundred bucks and turned out great =)

petep86

i dont suggest shaving rotors on any new cars, just get new ones. ull need them anyway,

Clinton Horn

The reason resurfacing rotors has become unpopular is because the rotor tends to warp. Removing material reduces the heat sinking capability of the disc. There is a minimum thickness (by law) cast on the rotor somewhere. Machining rotors should be pretty cheap. I have not had it done recently but I would think $20 ea would be a big price if you take them off and hand them to the shop. Mine (rear) are pretty heavily scored and I imagine I will have to replace them. For domestic cars they can be so cheap that resurfacing makes no sense. You are not going to risk anything but the cost of the work. They will not turn them below the minimum thickness. On the rear, they may be ok. HE22WA appears to be living proof.

vettdvr

MB doesn't recommend resurfacing but only replace.

Tom T

I just replaced my front pads and rotors. I agreed and would not turn the rotors because the new one are around 50 bucks (Zimmermann) at www.autopartswarehouse.com. With driving around and heated up the rotors, I still had to bang the heck outa old ones to come out. By that time the rotors are pretty bad and if you got them off easily, they would be too thin to turn. Why take the chance of warping the rotors.

paulv

I also, besides you and many other people believe that rotors warp. I found this info in a pro magazine explaining why we share that belief:

"Rotors do not warp. In the 1970s, someone came up with the whole “warping” theory and it has stuck. Why? Because to the layman, it makes sense. But, in reality it is a false explanation that does not hold water. Warping is actually two verifiable phenomena that can be experienced individually or in combination. Neither of these have anything to do with warping. These phenomena are Brake Torque Variation and Disc Thickness Variation. Brake Torque Variation (BTV) is a variation of torque across the face of the rotor causing the rotor to slip and catch as brake pads pinch the rotor. The differences in torque across the rotor may be caused by an
inconsistent rotor finish or the metallurgy of the rotor. Brake friction material deposited on rotor. BTV can be caused by uneven deposits of friction material. This might not cause a pulsation in the pedal, but it will cause
the vehicle to judder or vibrate. The second element of warping is Disc Thickness Variation (DTV). This measurement is the result of measuring the
thickness of the rotor surface at multiple spots around the rotor. Subtract the thickest part from the thinnest, and you will have a measurement for DTV.
As the thickness variations of the rotor pass through the caliper, the piston moves in and out. This action generates pulsations in the brake pedal that can be felt by the driver."

I'm convinced, and warping rotors has been removed from my vocabulary!!!

Regards,
paul...

SZMB

The single solid rotors in the rear are very cheap at $38 a piece (online price). It does not make sense to take the old rotors to an auto store and pay them $20 to resurface each rotor.

Clinton Horn

I stand corrected, runout by any other name is still....
I do find it interesting that we as a nation trumpet "green" living but very few are actually living their beliefs. No one rewinds starters / alternators, re-cap tires, grind valves, re-center pads/shoes, sheetmetal repair, I could go on forever. It is good for you to set your AC at 78 but I need mine at 70 for "health" reasons. Ditto public transportation, good for the masses but my time is much too valuable. I won't live to see it but when metals are most precious and humans even more plentiful, third world pracrices such as those above will not only become acceptable, they will be a fact of life.