Checking Grey Cast-Iron Brake Discs - Evaluating Cracks

WARNING: This page does not describe the selected car, but rather 10 other vehicles, including the 2012 Porsche Cayman, 2012 Porsche Boxster, 2011 Porsche Cayman, 2011 Porsche Boxster, and 2010 Porsche Cayman. 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 (Too Small)

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: Identifying Perforation Crack Length (Too Big)

Courtesy of PORSCHE CARS NORTH AMERICA, INC.

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

Fig 3: Locating Cracked Friction Plate

Courtesy of PORSCHE CARS NORTH AMERICA, INC.