Checking Grey Cast-Iron Brake Discs - Evaluating Cracks

WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2013 Porsche 911, 2012 Porsche 911, 2011 Porsche 911, 2010 Porsche 911, and 2009 Porsche 911. However, it is still accessible from the selected car via links, so may be relevant.

No need to remove from the vehicle as the perforation crack length is small (less than 5 mm).

Fig 1: Identifying Perforation Crack Length (Less Than 5 mm)

Courtesy of PORSCHE CARS NORTH AMERICA, INC.

Some perforation cracks are over 7 mm long.

Brake disc cannot be used (maximum permitted perforation crack length is 5 mm)!

Fig 2: Perforation Crack Length (Greater Than 5 mm)

Courtesy of PORSCHE CARS NORTH AMERICA, INC.

Brake disc with cracked friction plate rim -arrow-. Brake disc cannot be used!

Fig 3: Locating Damaged Friction Plate Rim

Courtesy of PORSCHE CARS NORTH AMERICA, INC.