Parking Brake Shoe: Service and Repair
Removing and installing brake shoes
Preliminary work
Information
^ The following illustrations show the right-hand side of the vehicle.
1. Remove rear wheels.
2. Remove the brake calliper from the wheel carrier and suspend it in the wheel arch (do not open brake hydraulics).
Removing
1. Disengage the parking-brake cable at the parking-brake lever.
Removing/fitting the parking-brake cable
2. Using a screwdriver, turn the adjustment device fully towards "release" through a wheel bolt threaded hole.
Releasing parking-brake shoes
3. Take off the brake disc after removing the countersunk screws (brake calliper removed). If a firmly seated brake disc cannot be removed by gentle tapping with a plastic hammer (only permitted for grey cast iron brake discs), evenly screw hexagon-head bolts into the two M8 threads of the brake disc, thereby pressing off the disc.
4. Remove compression springs -10-, adjustment device -2- and return spring -4-. Remove parking-brake shoes and return spring -5-.
Overview of parking-brake shoes
Installing
Information
^ Replace the brake calliper fastening screws after each removal. Fastening screws of various lengths are available.
Do not confuse the right and left brake discs during assembly (except for Carrera/Carrera 4 with standard brake system). Distinguishing characteristic: involute shape and spare part number. The flat surface of the brake discs is marked with R = right or L = left.
Overview of parking-brake shoes
Installation: The hooks (curved ends of the spring) of the compression spring -10- on the wheel carrier are positioned (engaged) correctly when the ends of the spring are pointing towards the center of the wheel -Arrows- (pointing downwards on the top brake shoe and upwards on the bottom brake shoe). Important note! Always inspect the top compression spring visually. Use your hand to check that the bottom compression spring is seated securely.
Adjustment: The brake shoes can be adjusted using the adjustment device -2-. No further adjustment is required because the parking-brake cables cannot be adjusted manually (self-adjusting system).
1. Lightly grease the adjustment device, pins on the actuating lever (spreading lever) and the sliding surfaces of the parking-brake shoes.
2. Install the actuating lever (spreading lever), brake shoes, return springs, compression springs and adjustment device. The spreading lever is a single-part assembly that cannot be disassembled.
Parking-brake shoes
3. Again check to ensure that the parking-brake shoes, adjustment device, return springs, compression springs and spreading lever are positioned correctly, and adjust them if necessary. Ensure that the hooks of the compression springs (curved ends of the spring) clasp the wheel carrier correctly. Examine the top compression spring -Arrow- visually through the opening in the wheel carrier -Arrow-. Use your hand to check that the bottom compression spring is seated securely.
Visual inspection of the top compression spring
4. Clean the levelling and centering surfaces on the brake disc and wheel hub. Then apply a very thin coat of Optimoly TA to the centering surface on the wheel hub.
5. Fit the brake discs. Do not confuse the right and left brake discs (except for Carrera/Carrera 4 with standard brake system in which both parts are the same).
6. Engage the parking-brake cable at the parking-brake lever.
Removing/fitting the parking-brake cable
7. Adjust the parking-brake shoes.
Subsequent work
1. Fit the brake calliper. Tighten new fastening screws to 85 Nm/63 ftlb. Ensure that the brake hose and brake line are positioned perfectly.
2. Fit rear wheels.