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 > VAS 6813 - PCCB Brake Disc Tester  at the three marked measuring points, -Arrows- with the brake disc installed. 

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

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.

   Measurement markings with new friction coating technology

   Information 

   • 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 approx. 2 to 5 units per brake pad set (depending on the axle and brake pad). 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).

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.

   Quick measurement with wheel

   1. 2.1 Measuring procedure: Align laser beam -2-  onto the measurement marking on the brake disc hub.

      Courtesy of PORSCHE CARS NORTH AMERICA, INC.

      Positioning tester on brake disc

      1	Tester 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.

      Courtesy of PORSCHE CARS NORTH AMERICA, INC.

      Measuring procedure/tester (roller stops)

   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. 

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.

   Markings and values (values given as examples only)

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.

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.

   Positioning tester on brake disc

   1	Tester 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.

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.

   Measuring procedure/tester (roller stops)

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

Courtesy of PORSCHE CARS NORTH AMERICA, INC.

Markings and values (values given as examples only)

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).