PCCB Disc

Checking front PCCB brake discs (wear assessment)
Includes:
1. Visual inspection for surface changes in the brake disc friction surfaces (wear assessment).
2. Check brake disc for minimum thickness (wear assessment/maximum permissible total wear 0.5 mm).
3. Check brake discs for edge damage (damage due to improper use).

General
Two conditions of criteria can make replacement necessary depending on the wear of perforated brake discs:
1. Surface changes in the brake disc friction surfaces at advanced stage.
2. Brake disc minimum thickness is not attained due to wear (material erosion due to friction).

In practice, both forms of disc erosion usually occur.
Only in seldom cases (for long-term race driving brake loads / very high temperature fluctuations in the friction surfaces), the surface changes can proceed so quickly that a premature disc change has to be performed.

1. Visual inspection of the surfaces of the brake disc friction surfaces

Note.
^ 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 operation 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.

The following illustrations (PCCB brake disc wear appearance) are to be used.

PCCB brake disc wear appearance





A. Friction area surface after normal brake load in street use operation.
^ No replacement necessary.





B. Friction area surfaces after a long run and occasional higher load.
^ Replacement not yet necessary.





C. End of service life of friction area surface or after highest load on a racing track.
^ Replace brake discs in the case of connected friction surface damage > 1 cm2.

2. Checking brake discs for minimum thickness

Note.
^ For perforated brake discs, the minimum thickness must always be measured on the inner or outer friction surface trace.
^ Brake disc thickness/wear limit: Maximum 0.5 mm total wear permissible. Refer to the technical data for the new dimension and other dimensions - Rep. Gr.46; Technical data/wear limits -GT2 or Turbo with PCCB.





- Measure the brake disc thickness dimension - X-, with a suitable micrometer screw or a brake disc gauge in the area of the inner and outer friction surface traces -arrow-.

3. Checking brake discs for edge damage

Note.
^ Irrespective of wear, a brake disc change can be necessary on the brake disc friction surfaces due to edge damage.
^ In this case, only one brake disc can be replaced if the friction area surface of the other PCCB brake disc is in order.





The following criteria applies to edge damage assessment:
^ Maximum permissible width/depth = 2 mm.
^ Maximum permissible length = 10 mm.
^ Maximum 3 damaged edge areas permissible.

Note concerning bores (perforations) in the brake disc friction surface

Caution. PCCB (Porsche Ceramic Composite Brake): Danger of material damage (danger of damage to the brake discs) if improper work is performed on the bores in the brake disc friction surface.
^ Clean the bores on PCCB brake discs with high-pressure cleaning equipment (only if necessary). In doing so, observe the environmental and safety regulations.
^ Do not machine (boring or countersinking is not permissible).





- Use high-pressure cleaning equipment to clean or expose the bores in the brake disc friction surface.