Performing Visual Inspection Of Friction Surfaces

Information 

• The friction surface changes occur due to material fatigue as a result of extremely high thermal load. These disc temperatures, which occur above all in racing conditions, cause a progressive material fatigue. 
• Effects on driving: The surface change worsens the smoothness of braking, decreases the disc strength and increases the brake pad wear and therefore makes a precautionary parts replacement necessary. 

Information 

Examples of different types of wear are shown below. The brake disc must be assessed according to these and then replaced if necessary

1. Friction surfaces after normal brake load while driving on roads. No surface fractures. > PCCB brake disc friction surface No replacement necessary. 

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.

   PCCB brake disc friction surface

2. Friction surfaces after a long run and occasional higher load. Isolated cases of associated surface fractures less than 1 cm²-arrow-  .

   No replacement necessary  as the associated surface fractures are < 1 cm² .

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.

   PCCB surface fractures

3. Friction surfaces at end of service life or after extreme stress on a race track. Associated friction surface damage > 1 cm²-arrow-  .

   Replace brake discs. 

   > 465119 REMOVING AND INSTALLING FRONT PCCB BRAKE DISC 

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.

   PCCB friction surface damage

   The best way to detect a surface fracture is by checking the wear indicators. Based on the wear indicators, this means that at least one wear indicator -arrow-  must have a surface fracture of > 80% (damage > 1 cm² /entire surface of a wear indicator with a surface area of approx. 1.2 cm² ).

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.

   PCCB surface burnout on wear indicator