00-05-22-002N Disc Brake Warranty Service and Procedures - (May 31 2013) Disc Brakes - part 9
In most instances rotor corrosion is cosmetic and refinishing the rotor is unnecessary.Corrosion — Pulsation Caused by Thickness Variation (Lot Rot / Low Miles — 0–321-km(0–200 mi):
At times more extensive corrosion can cause pulsation due to thickness variation.This usually happens when the vehicle is parked for long periods of time in humidtype conditions and the braking surface area under the pads corrodes at a differentrate compared to the rest of the brakingsurface area. Cleaning up of braking surfaces (burnishing) can be accomplished by10 – 15 moderate stops from 56– 64-km/h (35 – 40-mph) with cooling time between stops.If multiple moderate braking stops do not correct this condition, follow the “BrakeRotor Clean-Up Procedure” below.Corrosion — Pulsation Caused by Thickness Variation (without rotor flaking / highermileage — 3,200-8,000-km (2,000-5,000-mi):
In some cases, more extensive corrosion that is not cleaned up by the brake pad overtime and miles can cause the same type of pulsation complaint due to thickness variation.In these cases, the rotor surface is usually darker instead of shiny and a brakepad foot print can be seen against the darker surface. This darker surface is usuallydue to build-up, on the rotor material surface, caused by a combination of corrosion,pad material and heat. To correct this condition, follow the “Brake Rotor Clean-upProcedure” below.Corrosion — Pulsation Caused by Thickness Variation (with rotor flaking / higher mileage— 8,000 + km (5,000 + miles):
Important:In some flaking instances, cleaning-up this type of corrosion may require more rotormaterial to be removed then desired. Customer consideration should be taken in thesesituations and handled on a case by case basis, depending on the amount/percentageof rotor life remaining and the vehicle's warranty time and miles.BRAKE ROTOR CLEAN-UP PROCEDURE
Clean-up the rotors on an approved, well-maintained brake lathe to guarantee smooth,flat and parallel surfaces.