Checking Front Brake Discs - Evaluating Cracks
WARNING: This page is about a different car, the 2018 Porsche Macan and 2017 Porsche Macan. However, it is still accessible from the selected car via links, so may be relevant.
Different vehicle types have different brake disc sizes. This results in differences in terms of maximum crack length limits.
The maximum crack length limit is calculated as follows:
0.5 x a (-a - = width of friction surface in mm).
Width of friction surface a
The length of a crack can be measured with a steel rule, for example. → Brake discs
Brake discs
Information
Irrespective of the crack length, the brake disc must be replaced if the crack has extended as far as the outer and/or inner edge of the disc.
As a precaution, brake discs must be replaced when:
- the → Maximum crack length: 0.5 x a mm (a = friction surface width in mm) is exceeded!
- the → Maximum crack width: 1 mm is exceeded!
- the → Maximum crack depth: 1.5 mm is exceeded!