I notice a ridge along the perimiter of my front brake rotors. It brakes well without any problems, but was wondering if this is a sign for me to change rotors. I do not know how many miles the rotors has, but my pads looks ok. would appreciate for folks that may have noticed the same.

Though I am always ready to defer to our esteemed experts, I thought that I would give you a quick reply. The ridge is likely an indication that your pads do not cover the rotor all the way to the outside edge. This in itself is not a problem. It is an indication that your rotor is wearing. The rotor will have a minimum thickness stamped on it somewhere. You measure the rotor at several points and compare the value to the minimum. If you are under, then it is replacement time. A thin rotor will get hotter and cause brake fade and quicker pad wear. As some have said on the list, don't have the rotors turned - replace them. If it stops well now, and the rotors are thick enough, drive it and get ready to replace the rotors sometime in the future. They are cheap and must be replaced fairly often. Sometimes, a rock or other debris will become embedded in the pad and will cut a groove in the rotor. Small gouges are OK, but large cuts will eventually ruin the rotor.

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VR
1967 250SL

I am one of those proponents of changing the discs....Your 126 service CD's ( you do have them don't you ? )will tell you the minimum thickness of the rotor that is allowable. Skimming ( or turning ) a disc can never replace lost material they can only ever true them up and increase the surface braking area for a short time. Discs and pads are relatively cheap, change them when they near the minimum thickness for optimum braking and optimum peace of mind !

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1993 190E 2.0L (Euro.) sold
1991. 500 SEL (Euro.)
1991. 300 CE (Euro.) sold
1993. 500 E (U.S. spec.)

The ridge represents the wear since new. It can cause a squeek against new pads that occurs without braking. The risk of this occuring is the reason we eventually replace the rotors on a good performing system. In other words on my own car I would replace only pads till I had a noise or performance problem (feel, pulse, grab, groan, moan, pull, etc.) and then I would replace the rotors. As a technician I must decide that point before it occurs and we usually replace the discs every second set of front pads.

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Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician