Panamera S (970) V8-4.8L (2010)
Surface roughness of PCCB brake disc
2. Check surface roughness Rk of brake discs (max. 80 microns permitted) since this affects braking comfort (noises), braking behavior/pedal
pressure and brake-pad service life.
3. Check brake discs for minimum thickness -X-. The minimum brake disc thickness (e.g. Min. Th. 29.7 mm) is stamped on the brake-disc chamber.
Minimum thickness -X- of PCCB brake disc
4. Check brake discs for edge damage -arrow- (damage due to improper use).
Edge damage on PCCB brake disc
General information on replacing worn PCCB brake discs
Three criteria governing the condition of the parts can make replacement necessary depending on the wear of PCCB brake discs:
1. Surface changes in the brake disc friction surfaces (material fatigue/wear) at an advanced stage (indication of wear: connected friction surface
damage > 1 cm2).
2. Surface roughness of the brake disc friction surfaces too great (roughness depends on mileage and load).
3. Brake disc minimum thickness is not attained due to wear (material erosion due to friction).
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In practice, all three forms of brake disc erosion usually occur.
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Only in rare cases (as a result of long-term motor-racing brake loads/very high temperatures on the friction surfaces), surface changes can progress
so quickly that the brake discs may need to be changed earlier than planned.
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Brake discs that have turned blue at the brake-disc chamber and/or brake calipers that have turned a strong brown color are clear indications of
high loads over a long period of time, e.g. on the race circuit.
Replacing brake discs (notes/decision-making aid)