Checking brake discs for minimum wear value

Information 

The pictures shown in this document may differ from the original  .

Information 

• Check PCCB brake discs for wear during every service and when changing the brake pads! Brake disc remains installed  .
• Always carry out wear assessment on the brake discs and check the condition of the brake pads before and after every race track use (component temperatures are significantly higher than temperatures during "normal" driving)  .
• The brake disc temperature must be between → Temperature: 0°C and → Temperature: 40°C when taking measurements  .
• The tester must be checked before taking measurements and may have to be calibrated. Follow the operating instructions provided by the equipment manufacturer! 
• Important for quick measurement: A metallic heat shield will lower the measured value  .

1. Measure values using test equipment for PCCB brake discs WE 1578  at the three marked measuring points with the brake disc installed  .

   The following description distinguishes between quick measurement (as in 2.) and exact measurement (as in 3.)  .

   Information 

   • The drop in the value using a brake pad set depends very much on the driving conditions  .
   • The remaining service life of the brake disc can be estimated using the previously stored data and measured values recorded during service intervals/workshop visits based on the mileage  .
   • The value is reduced by 2 to 5 units (depending on axle) for each brake pad set  . Not valid for race track use and if brake pads not approved by Porsche are used  .
   • Carry out wear assessment on the brake discs and check the condition of the brake pads before and after every race track use (component temperatures are significantly higher than temperatures during "normal" driving)  .
2. Quick measurement:  Brake calliper fitted (with or without wheel).
   1. 2.1. Measuring procedure: Align laser beam -2-  onto the measurement marking on the brake disc hub.
      1. Test equipment VAS 6813
      2. Laser beam for positioning
      3. Measured value display

      When taking measurements, the tester must be positioned over the entire surface of the brake disc with the roller stops and the underside of the device.

   2. 2.2. Compare the values you read off with the wear value -3-  (lower value).

      If the wear value (lower value) is reached or if the measured value is less than the wear value at a measuring point, carry out an exact measurement  .

3. Exact measurement: Wheel and brake calliper removed  .

   Turn the measurement marking and brake disc so that the tester can be placed at the position at which the brake calliper was removed.

   The removed brake calliper must not be placed closer than 50 mm to the back of the brake disc when taking measurements.

   Always follow the operating instructions for the tester to make sure you are using it correctly  .

   1. 3.1. Measuring procedure: Align laser beam -2-  onto the measurement marking on the brake disc hub.
      1. Test equipment VAS 6813
      2. Laser beam for positioning
      3. Measured value display

      When taking measurements, the tester must be positioned over the entire surface of the brake disc with the roller stops and the underside of the device.

   2. 3.2. Compare the values you read off with the wear value -3-  (lower value).

      If the wear value (lower value) is reached or if the measured value is less than the wear value at a measuring point, replace the brake discs on both sides of the axle.

      Applies to exact measurement (not quick measurement)  .