Check Brake Disks For Wear - AP42.10-P-4258-02RQ

Model 190, 197, 205, 212, 213, 217, 218, 222, 231, 253, 290 with code B07 (AMG - ceramic brake system) 

Determine the wear on the brake disks by evaluating the wear indicators (1) using test films (2) only.

Parts ordering notes: 

Part number: A 197 001 77 99.

Designation: Test film.

Quantity: As required.

There are 3 wear indicators (1) each on the inner and outer friction surface.

Do not use the dimension and weight specifications on the brake disk bowl for determining the level of wear.

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1. Detach test film (2) from carriers, place in the center on the wear indicators (1) and press on. Mark position of wear indicators (1) on test film (2).
2. Photograph all the test films (2) using a digital camera several times.

   Distance approx. 10 cm, select macro function without flash.

3. Choose a representative photo of each wear indicator (1) on the computer monitor and zoom to an edge length of min 3.5 cm.
4. Count all the squares in which burnt surfaces (light points) are visible and enter the number in the table. One square < 50% burnt out counts as a 1/2 square. One square ≥ 50% burnt out counts as 1 square.
5. Model 217, 222 with code B07 (AMG - ceramic brake system)

   Add up the number of rejected squares for all wear indicators (1).

   If the sum of the rejected squares for all wear indicators (1) on a brake disk is ≥ 96, ↓

   replace both brake disks and all brake pads on the axle.

6. Except model 217, 222 with code B07 (AMG - ceramic brake system)

   Add up the number of rejected squares for all wear indicators (1).

   If the sum of the rejected squares for all wear indicators (1) on a brake disk is ≥ 96, ↓

   replace affected brake disk and brake linings.

7. Detach all test film (2) and use dry cloths to wipe away any residue.
8. Archive photos.

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Example (A): 

17 squares < 50% = 17 x 1/2 square = 8.5 squares.

8 squares ≥ 50% = 8 x 1 square = 8.0 squares.

16.5 squares.

Example (B): 

11 squares < 50% = 11 x 1/2 square = 5.5 squares.

14 squares > 50% = 14 x 1 square = 14.0 squares.

19.5 squares.