Wear Limits

Technical data/test values and brake wear limits








Technical values





Test values and wear limits for 18" brake system (V8 + Turbo)

Information
Depending on the extent of wear on cast iron brake discs, two condition criteria can make replacement necessary:

Formation of cracks at advanced stage on the brake disc friction surfaces.
Minimum brake disc thickness is not retained due to wear (material erosion due to friction).





Possible complaints

Damage due to lack of use (rusting). This causes vibrations in the steering wheel, noises and brake pedal pulsation.
Brake disc becomes distorted as a result of serious driving.
Too much lateral runout when new brake discs are fitted on dirty or distorted wheel hubs.

Procedure

Check brake disc for cracks, minimum thickness, lateral runout, thickness tolerance, flatness and surface roughness.
If necessary, (depending on the actual brake disc thickness and the brake disc wear limit) machine the brake disc using one of the disc brake dressing machines approved by Porsche.
The brake disc must only be reworked symmetrically, i.e. evenly from both sides! Observe the operating instructions for the disc brake dressing machine!