PeachParts Mercedes-Benz Forum - View Single Post - warped rotors

automch · #35 06-15-2007, 05:04 PM

I am ASE certified and for many years worked as a Front End, Brake & Power Steering Specialist. Brake rotor warpage is a problem that has been ongoing since eliminating asbestos in 1990. That's not to say it didn't exist proir to 1990 but it was usually caused by abusive driving, mechanics with uncontrolled air guns, cheap pads etc. One of the problems after 1990 was that the pad material would actually weld itself to the rotors causing pulsations.

Additionally, in the past few years many smaller producers of quality automotive parts have been bought up by conglomerates and as a result quality has suffered. Many of the old trustworthy aftermarket brands have sunk to a new low in quality or just dissappeared. Most all of those left now import from China or Mexico which tend to be inferior. Raybestos still has American or Canadian made rotors as of the last time I bought them. These are still good quality. However many parts houses sell "White Box" Raybestos rotors which are from China or Mexico. Avoid them like the plague. If you follow these rules you will minimise the possibility of pulsation problems.

1. Buy strictly OEM or known quality aftermarket rotors

2. If possible OEM or "Ceramic" replacement pads.

3. Rotors should never be machined below tolerance specs.

4. Wheels should be tightened in a star pattern with an appropiate "Torque Stick" if using an air gun, or torque wrench if by hand

5. Break-in of new pads should be "Gentle" for the first 200 miles. Avoid panic stops. Several slow stops from 45 to 0 with cool down time in between helps the process of eliminating high and low spots in the pads so that the full surface of the pads contact the rotors and help dispense the heat.

It is still possible to have pulsation failures when you follow these but at least you've done all you coould do to prevent it from happening. HTH.