Test Values/Wear Limits For 911 C2/C4 And 911 C2S/C4S - PCCB Brakes (Option)
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).
| Location | Description | Type | Basic value | Tolerance 1 | Tolerance 2 |
|---|---|---|---|---|---|
| Pad thickness, front | Measured value | approx. 12.0 mm | |||
| Pad thickness, front (wear limit) | Measured value | 2 mm | |||
| Pad thickness, rear | Measured value | approx. 12.0 mm | |||
| Pad thickness, rear (wear limit) | Measured value | 2 mm | |||
| Brake disc thickness, new (front) | Measured value | 34 mm | |||
| Brake disc thickness, new (rear) | Measured value | 28 mm | |||
| Brake disc wear limit, front | Minimum brake disc thickness (wear limit) is stamped on the brake disc hub. Example: Min. Th. 33.7 mm | Measured value | mm (Read value on brake disc hub) X.XX |
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| Brake disc wear limit, rear | Minimum brake disc thickness (wear limit) is stamped on the brake disc hub. Example: Min. Th. 27.7 mm | Measured value | mm (Read value on brake disc hub) X.XX |
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| Wear limit: Surface changes in 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 changes | Values and procedure for: checking front 46 51 02 PCCB brake discs/checking rear 46 54 02 PCCB brake discs. | ||
| Thickness tolerance of brake discs (max.) | Measured value | 0.02 mm | |||
| Lateral runout of brake disc (max.) | Measured value | 0.03 mm | |||
| Lateral runout of wheel hub (max.) | Measured value | 0.03 mm | |||
| Lateral runout of brake disc when installed (max.) | Measured 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 | Diameter | 181 mm | |||
| Width of parking-brake shoe | Measured value | 25 mm | |||
| Thickness of parking-brake pad | Measured value | 4.5 mm | |||
| Thickness of parking-brake pad, wear limit | Measured value | 2 mm |