Raise and support the car, remove the wheels.
Measure the thickness of the brake discs. In the workshop, a special tool (035) is used for this, since a "ridge" appears on worn discs. The thickness of the disc can be measured with a caliper with a vernier, but in this case, a 3 mm thick pad must be installed on both sides of the disc (or one coin at a time). To obtain the true thickness of the disc, subtract 6 mm from the measured value.
| Thickness, mm | Front disc | Rear disc |
| New disks | 12,6 | 10 |
| Wear limit | 11,1 | 8.6 |
| Metal shield | 10.6 | 8,3 |
When the maximum permissible wear is reached, the disks must be replaced.
If there are large cracks or grooves on the discs that are more than 0.5 mm deep, the discs must be replaced.
[Article was borrowed from the website MercedesMan]