Checking Front Brake Discs - Minimum Thickness
Information
Normally, brake discs are used until the maximum wear dimension is reached.
> 4600TW GREY CAST-IRON BRAKES - TECHNICAL VALUES AND WEAR LIMITS
Only in a few exceptional cases (if there is deep scoring or corrosion of the friction surface) is it advisable to skim the brake discs.
Only the brake disc dressing machines approved by Porsche AG should be used (Refer to the appropriate service information. ).
- Only "as new" brake discs may be reworked!
- Only rework brake discs symmetrically and evenly from both sides.
Since pressure forces of the brake pistons on the brake pad vary, different areas of wear arise on the friction surface. The brake disc can basically be divided into two areas of wear:
-A- Outer and inner wear area.
-B- Medium wear area (highest degree of wear).
Wear areas A and B
- Measure the brake discs using a suitable micrometer screw at least three different places (-A, B, C-
), offset by 120°.
Measurement points for brake disc thickness
- If the measured value at one or more measurement points is less than the required value engraved on the brake disc hub: Replace brake disc.