Brakes on ML 320
 

My dealer just told me I had to replace pads and rotors on my 2000 ML 320 with 30000 miles and nothing but normal suburban driving.

My sense is that if the rotors required replacement at this early stage MB didn't perform the right service at the scheduled intervals or the rotors were defective. We had previously changed the front pads at around 18.000 miles.

I understand the rotors cannot be ground.

The only way the rotors can't be resurfaced is if they are BELOW min wear SPECS. WE resurface Benz rotors every day for WARPAGE!!

Life of Rotors
 

Can you give me any guidance on the expected life of rotors

I hear that all the time..........but my question is why does MB not recommend that you resurface rotors?......I have never seen a dealer that would do it........



Warren
1992 300SD
Columbus Ohio

Basically it’s a safety issue. If you always have rotors in spec (read that, newish) they will dissipate heat more effectively and ultimately work better and have less chance of failing. Bringing a truck weighing in at around 2.5 tones to a stop is no trivial matter. Also, the rotors are pretty inexpensive. If you are comfortable at DIY you can buy parts here (at partsshop) and cut the cost significantly. OTOH, if MB Doc says he does it every day, I would trust him! I’ve read his posts for years here and he is never wrong.

MB dealers don’t fix or re-manufacturer stuff. As a rule they replace parts with new. By the time you have labor to R&R the rotors, labor to re-surface them, add the standard MB dealer warranty, you (as a dealer) are at a deficit with used rotors.

The duty cycle of brake parts varies by a factor of 4x more or less due to use. If most use is freeway, you’ll get very long life (duh, if you only hit your brakes every 100 miles they will undoubtedly last a long time), but if you do stop and go, I’ve heard as little as 11K miles for the pads and about 22K miles for the rotors. The fronts wear a lot faster than the rears.

but if you are a dealer why would you performan operation not recommended by the manufacturer?.....seems like sure death there......and since rotors are cheap it kinda negates the resurfacing of the old.........brings to mind having a VCR fixed in this day and age


Warren
1992 300SD
Columbus Ohio

Rotor Life...
 

I generally like to re-surface my rotors every other brake pad change.
Pad change one: De-glaze (DA Sander)
Pad change two: Re-surface
Pad change three: De-glaze (DA Sander)
Pad change four: New rotors
If I had the equipment to re-surface my own rotors, I would take the minimum material off when the rotors need re-surfacing the the first time and that would probably allow me to re-surface them a second time, but the guys at the autoparts stores usually take off the maximum amount of material so they don't have to make 2 cuts on your rotor (and be able to $ell you replacement rotors regularly).

Dealers don't. The more direct answer to your question gets down to differing perceptions of value: Safety at what cost?