Test Values/Wear Limits
Information
The following condition criteria can make replacement necessary depending on the wear of the PCCB brake discs:
- Surface changes in the brake disc friction surfaces at an advanced stage.
- Minimum brake disc thickness is not retained due to wear (material erosion due to friction).
- Check the friction surfaces using > VAS 6813 - PCCB brake disc tester .
| Location | Description | Type | Basic value | Tolerance |
|---|---|---|---|---|
| Pad, front | PCCB | Thickness | 10.4 mm | |
| Pad, front (wear limit) | All | Thickness | 2 mm | |
| Pad, rear | All | Thickness | 11.3 mm | |
| Pad, rear (wear limit) | All | Thickness | 2 mm | |
| Brake disc, new (front) | All | Thickness | 36 mm | |
| Brake disc, new, rear | Grey cast iron | Thickness | 30 mm | |
| Brake disc, new (rear) | PCCB | Thickness | 32 mm | |
| Brake disc, front (wear limit) | Grey cast iron | Thickness | 34 mm | |
| Brake disc, rear (wear limit) | Grey cast iron | Thickness | 28 mm | |
| Brake disc wear limit, front - PCCB | Brake disc minimum thickness (wear limit) is stamped on the brake disc hub. Example: Min: Th. 33.7 mm | Thickness | (Read value on brake disc hub) X.XX mm | |
| Brake disc wear limit, rear - PCCB | Brake disc minimum thickness (wear limit) is stamped on the brake disc hub. Example: Min: Th. 27.7 mm | Thickness | (Read value on brake disc hub) X.XX mm | |
| Wear limit PCCB: Surface change on front and rear brake discs | Wear limit: Connected surface fracture > 1 cm2 and/or surface roughness of brake disc > 80 micrometer. Replace PCCB brake discs on each axle. | Surface change | Values and procedure for: Checking front 465102 PCCB brake discs/checking rear 465402 PCCB brake discs | |
| Thickness tolerance of brake discs (max.) | All | Value | 0.02 mm | |
| Maximum brake disc runout | All | Value | 0.03 mm | |
| Maximum wheel hub runout | All | Value | 0.03 mm | |
| Maximum installed brake disc runout | All | Value | 0.06 mm | |
| Push-rod play | Measured at brake pedal plate | Measured value | approx. 1 mm | |
| Diameter of parking-brake drum | Parking brake (electrically actuated, drum brake acting on the rear axle) | Diameter | 180 mm | |
| Diameter of parking-brake drum (wear limit) | All | Diameter | 181 mm | |
| Width of parking-brake shoe | All | Measured value | 25 mm |