Brake Master Cylinder

Brake Master Cylinder

• If the vehicle has a TFSI engine, then the noise amplifier must be removed and installed. Refer to => [ Noise Amplifier, TFSI ] Service and Repair.

• The noise amplifier is inside the engine compartment in front of the brake booster.

Special tools, testers and auxiliary items required

• Torque wrench (V.A.G 1331)

• Brake filler/bleeder unit (V.A.G 1869)

• Brake filler/bleeder unit suction adapter (V.A.G 1869/4)

• Brake filler/bleeder unit (VAS 5234)

• Sealing plugs repair kit, Part no. (1H0 698 311 A)

• Vehicle Diagnosis, Testing and Information System (VAS 505x)

Removing






- Remove engine cover upward in - direction of arrow -.

- Depending on the engine installed, remove the noise amplifier. Refer to => [ Noise Amplifier, TFSI ] Service and Repair.

- Remove brake light switch. Refer to => [ Brake Light Switch ] Brake Light Switch.

- To protect against escaping brake fluid, place enough lint-free cloths in the area below the master brake cylinder.

- Extract as much brake fluid as possible from brake fluid reservoir using (VAS 5234) or (V.A.G 1869/4).

• Do not, under any circumstances, allow brake fluid to come into contact with any fluids containing mineral oil (oil, gasoline, cleaning solvents). Mineral oil damages the sealing plugs and boots of the brake system.

• Brake fluid is poisonous. NEVER siphon brake fluid with your mouth! Also due to its corrosive effect, brake fluid must not come into contact with paintwork.

• Observe disposal regulations.

- Connect connector on brake fluid level warning switch.

- Disconnect brake lines - 3 - at brake master cylinder and seal brake lines with sealing plugs from repair kit.






- Remove brake master cylinder nuts - 1 -.

- Remove heat shield.

- Unclip brake fluid reservoir at position - 2 - and pull upward and off.

- Remove brake master cylinder from brake booster.

Installing

Installation is the reverse of removal, with special attention to the following:

- Replace sealing ring between brake master cylinder and brake booster.

- When replacing brake master cylinder, ensure pressure rod in brake booster is seated correctly.

- Use new nuts - 1 -. Note torque: 20 Nm






- Press brake pedal down a bit, this allows the brake master cylinder to be guided into pressure rod more easily.

- Install brake lines - 3 - on brake master cylinder. Note torque: 14 Nm

- Install brake light switch. Refer to => [ Brake Light Switch ] Brake Light Switch.

- Install the brake fluid reservoir. Refer to => [ Brake Fluid Reservoir ] Service and Repair.

- Depending on the engine installed, install the noise amplifier. Refer to => [ Noise Amplifier, TFSI ] Service and Repair

- Brake system bleeding, refer to => [ Brake System Bleeding ] Brake System Bleeding.

- Initiate brake pressure sensor basic setting.

• Use the (VAS 505x) for this.

- Perform ESP driving and system test.

(VAS 505x).

- Under chassis

- Brake system (Repair Group 01; 45)

- 01- On Board Diagnostic (OBD) capable systems

- 03- Brake electronics ABS/ESP Mark 60 si

- J104- ABS/ASR/ESP Control Module, Functions

Make sure the brakes are working correctly before driving the vehicle for the first time.