Notes On Evaluating Brake Disks With And Without Wear Holes - AH42.10-P-9406-14A
MODEL ALL (4xWD, CAR, smart)
Perforated brake disk with wear bores
The outer wear bore (11), center wear bore (12) and the inner wear bore (13) on perforated brake disks are located 120° relative to one another between the crescent-shaped brake disk bores (14).
Brake disk with wear bores
The outer wear bore (11), center wear bore (12) and the inner wear bore (13) are located 120° relative to one another.
General
Brake disks with wear bores were introduced in assembly production from model series 205 onwards. Therefore, within a model series brake disks with wear bores and brake disks without wear bores can be installed. Mercedes-Benz genuine brake disks are available for the corresponding model series with wear bores only.
On each axle the brake disk with the most advanced level of wear should always be used for assessment.
The outer wear bore (11) and center point wear bore (12) indicate the degree of wear. As long as they are both visible, new brakepads can be installed on the brake disks, insofar as the brake disks do not exhibit any further problems.
The inner wear bore (13) indicates the absolute wear limit. If only the inner wear bore (13) is visible, the brake disks can still be used with the current brakepads, insofar as the brake disks do not exhibit any further problems. New brakepads may no longer be installed.
If the inner wear bore (13) is no longer visible, the brake disks must be replaced.
For brake disks with deeply contoured ridging on the outer edge and with no visible wear bores, the wear limit with the measurement method must be used to check the brake disks, as the brake disks have either no wear bores or they are so worn that they are no longer visible.