Contents: Removal ⬇ Installation ⬇
Note: The following work is performed only when replacing the brake caliper and precedes subsequent repair work.
Note:
- Do not use power or pneumatic tools to loosen or tighten the brake caliper guide pin bolts.
- When holding the guide pin from rotating using an open-end wrench, avoid contact of the wrench with the brake caliper. Otherwise, the caliper installation may change, which will lead to pulsation during braking.
Caution: Do not use brake fluid that is not recommended by the manufacturer. Also, do not reuse brake fluid after draining. Do not use brake fluid that has been stored for a long time in a non-sealed container, as the fluid is hygroscopic and can absorb moisture from the surrounding air. This circumstance may lead to the failure of the hydraulic drive system when using such fluid.
Caution: Always install new brake pads, and replace them on both sides of the vehicle simultaneously to prevent the vehicle from pulling when braking.
Caution: Brake fluid is very aggressive to plastic and painted parts. Therefore, avoid getting liquid on the paintwork. Otherwise, rinse the affected area with plenty of running water.
Removal
1. Remove the rear wheel by unscrewing its mounting bolts.
Note: The electromechanical parking brake pistons must be returned to their original position using a special diagnostic position.
Caution: Before returning the brake caliper pistons to their original position, remove any excess brake fluid from the master cylinder expansion tank.
2. Move the pistons to their original position using special diagnostic equipment.
3. Unscrew the mounting bolts (arrows) of the parking brake activation electric motor, shown in the figure below.
4. Pull out the parking brake motor and set it aside without disconnecting the wiring harness connector from it.
5. Connect the hose (1) shown in the figure below to the bleed nipple.
6. Open the bleed nipple.
7. Press the brake pedal and fix it in this position using the special tool VAG 1869/2.
8. Close the bleed nipple and remove the bleed container with brake fluid.
9. Disconnect the brake hose from the brake caliper.
Caution: There is a high risk of injury when removing the retaining spring. The spring may come off and get into your eyes, so you need to hold it securely when removing it.
10. Using a screwdriver (A), remove the retaining spring (1) and holes (arrow) as shown in the figure below. When performing this operation, the spring must be held with one hand.
11. Remove the protective covers (arrows) shown in the figure below.
12. Remove both guide bolts from the brake caliper using the T10503 7mm bit and a ratchet wrench as shown in the figure below.
13. Remove the brake caliper assembly from the support bracket.
Installation
1. Install the brake caliper onto the support bracket and secure it with new self-locking bolts.
Note: Check and ensure that the annular groove and contact surface for the parking brake motor are thoroughly clean.
2. Install a new sealing ring.
3. Turn the spindle back using the Torx E11 head until the electric motor can be installed in place.
4. Carefully install the parking brake servo motor into the caliper, making sure the O-ring is seated properly.
5. Turn the parking brake motor until the hole is aligned with the threaded part.
Note: Ensure that the parking brake servo motor is installed flush with the brake caliper.
6. Tighten the mounting bolts first by hand, then tighten them to the required tightening torque.
7. Connect the brake hose to the caliper.
8. Perform operations to remove air (bleed) from the hydraulic drive of the brake system (for more details, see the relevant section in this chapter).
9. Set the basic settings of the braking system.
10. Install the rear wheels and tighten their mounting bolts to the required tightening torque.
Note: Check the brake fluid level in the master cylinder expansion tank.