Brake System Audi A6 С6

Allocation of PR. No. for brakes

The brake system installed in a vehicle is documented on the vehicle data sticker via relevant PR number.

The vehicle data sticker is located in spare wheel well and in Maintenance booklet.

The front wheel brakes PR no. is found at item - A -.

Scheme 1

The rear wheel brakes PR no. is found at item - B -.

1. Allocation .
2. The following table explains PR numbers. This is important for brake caliper/brake disc and brake pads.

Brakes

Vehicles with front and rear disc brakes

Brake discs

Note. Hairline cracks on brake disc friction surfaces are often observed during brake repairs. Hairline cracks up to 10 mm long are not a technical flaw and are not cause for brake disc replacement. Brake discs with friction surfaces that have worn through should be replaced.

General information

The wheels are driven by the test stand.

When testing, place selector lever in driving position N for vehicles with automatic transmission and in neutral position for vehicles equipped with manual transmission.

Follow instructions issued by manufacturer of brake test equipment.

Note. Electronic brake control systems are inoperative when the ignition is switched off.

Front Wheel Drive (FWD) vehicles

The brake test is to be performed on a one-axle roller test stand.

The test speed must not exceed 6 Km/h, otherwise, due to the time-delayed run-up of the rollers, the brakes may want to lock up (EDL regulation).

Test stands approved by Audi meet these requirements.

Vehicles with all-wheel drive

Test on a one-axle roller test stand for all-wheel drive vehicles

During this test, the wheels of one axle are driven in opposite directions, to prevent delivering power to the other axle.

The test speed must not exceed 6 Km/h, otherwise, due to the time-delayed run-up of the rollers, the brakes may want to lock up (EDL regulation).

Test stands approved by Audi meet these requirements.

Test on a one-axle roller test stand

The test speed must not exceed 6 Km/h, otherwise, due to the time-delayed run-up of the rollers, the brakes may want to lock up (EDL regulation).

Test stands approved by Audi meet these requirements.

EPB (electromechanical parking brake) on brake test stand

Test sequence

1. Drive in vehicle with rear wheels on test rollers and do not switch ignition off.
2. As soon as the rollers reach a speed between 3 km/h and 9 km/h, "TUV mode" is activated.
3. A cancelled-out yellow electromechanical parking brake system --> appears in the instrument cluster Owners manual; Instruments and indicator lights

The EPB functions as follows

The brakes don't close at once, but rather close a bit each time the button is pressed (parking brake pressure switch). Tension sufficient for measuring will be reached after 3 steps.

One press on the button releases the brakes again.

Prerequisite for "TUV mode"

1. Ignition on
2. Front wheels, speed greater = 0 km/h
3. Rear wheels, speed min. = 3, max. 9 km/h.

Brake fluid is hygroscopic, i.e. it has the capability to absorb water and moisture from the air.

Scheme 2

If water has been absorbed, the boiling point will drop, i.e., during high braking temperatures the brake fluid may develop steam bubbles and cause the brakes to fail.

Over time, brake fluid will darken in color. Dark-colored brake fluid does not specify anything about its quality. The coloring occurs through chemical reactions and can occur after a short time (several weeks), especially in vehicles with ABS.

Even the smallest amount on a seal or boot can cause the part to change and thereby affect the function of the brake system. The results of an unclean brake system first show themselves months later, causing increased repair costs, especially on vehicles with ABS.

Scheme 3

A = Boot - original size

B = Boot - Swollen through contact with mineral oil

It is implied by the previously mentioned points that

Keep containers of brake fluid closed securely. This is to make sure that no oil, dirt or cleaning materials and no air moisture can enter the container.

Store containers of brake fluid away from oil (even hydraulic oil) and cleaning fluids to prevent an accidental mixing of both fluids or even filling the brake system with the wrong fluid.

The use of brake fluid approved by AUDI is recommended

Notes for repair work on ABS

1. Before performing repair work on the Anti-lock brake system, determine the cause of the malfunction using On-Board Diagnostics (OBD).
2. When installing a new hydraulic control unit, coding must be checked Vehicle diagnosis, test, and information system VAS 5051.
3. Switch ignition off before installation work. On vehicles with coded radio unit, determine code and disconnect battery Ground (GND) strap.
4. When working with brake fluid, observe relevant safety precautions and notes --> «Brake fluid»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system) .

1. With all work that requires hydraulic system to be opened, brake system should be bled (e.g. with Brake Filler/Bleeder Unit VAS 5234) --> «Pressure leak test»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system__pressure-leak-test) . High and low pressure testing should also be performed on brake system --> «High and low pressure testing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system__high-and-low-pressure-testing)
2. During final road test, ensure that an ABS-controlled braking is performed at least one time (pulsing must be felt in brake pedal). See Vehicle Diagnosis, Testing and Information System VAS 5051
3. Absolute cleanliness is required when working on the Anti-lock brake system, it is not permitted to use any products which contain mineral oil, such as oils, greases etc.
4. Thoroughly clean all unions and adjacent areas before loosening. Do not use aggressive cleaning agents such as brake cleaner, fuel, thinners or similar chemicals.

1. Place parts that have been removed on a clean surface and cover.
2. Carefully cover over opened components or seal, if repairs are not carried out immediately. (Sealing plugs, use repair kit 1 H0 698 311 A)
3. Only use lint-free cloths.
4. Only unpack replacement parts immediately prior to installation.

1. Only use genuine packed parts.
2. Do not work with compressed air and do not move vehicle while the system is open.
3. Make sure that no brake fluid enters plug connectors.

Vehicle Diagnostic, Testing and Information System VAS 5051 , connecting and selecting function

Special tools, testers and auxiliary items required

Scheme 4

1. Vehicle diagnostic, test and information system VAS 5051

Scheme 5

1. Connect the VAS 5051/5a diagnostic cable connector to diagnostic connection.

Scheme 6

1. Switch on tester - arrow -.

The tester is ready for operation when it displays the image (photo) of a vehicle.

1. Switch on ignition.
2. Touch the field/button on screen: Guided Fault Finding.
3. Select one after another

1. Brand
2. Type
3. Model year
4. Version

1. Engine code

1. Confirm entered data.

Wait until tester has checked all control modules installed in the vehicle.

1. Press Goto button and select "Function/Component Selection" function.
2. Select on display "Suspension"
3. Select on display "Brake system"
4. Select "01-On Board Diagnostic (OBD) capable system..." indicated on display.

1. Select on display "Anti-lock brake system...".
2. Select on display "Function".

Now, all possible functions of Anti-lock brake System (ABS) installed in vehicle are displayed.

1. Select desired function on display.

Scheme 7

1 - Traction Control Indicator Lamp K86

1. Component location: In instrument cluster
2. More information Owners Manual
3. It blinks when driving if ESP engages regularly.
4. It comes on as a function test when ignition is started.

1. It comes on when ignition is switched on and goes out after driving a short distance when ESP performs a system-specified adaptation process on its sensors.
2. It comes on when ESP or ASR lamp malfunctions
3. Comes on if ESP is switched off.
4. It comes on if there is an ABS malfunction because the ESP system works together with ABS.

1. If battery was disconnected and connected, the vehicle was started by jump starting or the battery is very low, the ESP performs an adaptation sequence on its sensors during the first several meters driven. The indicator light comes on for this. The indicator light goes out as soon as the adaptation process is completed.
2. If indicator light comes on immediately after starting engine, there is a system-directed shut down of the system. In this case, ESP can be reactivated by switching ignition on and off. If the indicator light goes out, the system is completely functional again.

2 - ABS warning light K47

1. Component location: In instrument cluster
2. More information Owners Manual
3. The indicator light comes on for several seconds when ignition is switched on or engine is started. The indicator light goes out after an automatic test has been completed.

There is an ABS malfunction

1. The indicator light does not come on when ignition is switched on.
2. The indicator light goes out again after a few seconds
3. The indicator light comes on when driving.
4. The vehicle can still be braked with standard brake system, that is, without ABS.

1. The ESP indicator light also comes on when there is an ABS malfunction.

Malfunction in complete brake system.

1. If ABS indicator light comes on together with brake system indicator light, not only is the ABS faulty but it must be assumed that the brake system is as well.
2. If the brake system malfunctions, the symbol appears in instrument cluster display.

3 - Brake System Warning Lamp K118 symbol

1. Location in instrument cluster in Driver Information System
2. If indicator light blinks, there is a brake system malfunction.

The brake system indicator light blinks when brake fluid is too low or the ABS system or parking brake is malfunctioning.

1. More information Owners Manual

4 - Steering Angle Sensor G85 with ESP

1. Component location: Installed in coil ring with slip ring on steering column --> «69 - PASSENGER PROTECTION - AIRBAGS, SEAT BELTS»(/audi/a6/6-2004-2008/remont/gauges-instrument-panels/#body-interior)
2. Perform zero adjustment.

Vehicle diagnostic, test and information system VAS 5051

5 - Parking Brake Pressure Switch F234

1. Component location: In center console
2. Removing and installing --> «Parking Brake Contact Switch F321 , removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system__parking-brake-contact-switch-f321)

6 - ESP-Sensor Unit G419

1. Component location: under center console extension
2. Can be tested in "Guided Fault Finding" using Vehicle diagnosis, testing and information system VAS 5051
3. Observe installation instructions

> ESP Sensor Unit G419 , removing and installing

7 - Wheel bearing/hub unit

1. The ABS sensor ring is installed in the wheel bearing

8 - Right/Left Rear ABS Wheel Speed Sensor G44/G46

1. Can be tested in "Guided Fault Finding" using Vehicle diagnosis, testing and information system VAS 5051
2. Replacing «Speed sensor on rear axle, removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system__speed-sensor-on-rear-axle-removing)

9 - Diagnostic connection

1. Component location: Cover in driver footwell
2. > (Scheme 8)

10 - Wheel bearing/hub unit

1. The ABS sensor ring is installed in wheel bearing

11 - Right/Left Front ABS Wheel Speed Sensor G45/G47

1. Can be tested in "Guided Fault Finding" using Vehicle diagnosis, testing and information system VAS 5051
2. Replacing «Speed sensor on front axle, removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system__speed-sensor-on-front-axle-removing)

12 - ABS Hydraulic Unit N55 with ABS Control Module J104

1. The hydraulic control unit is comprised of hydraulic unit and control module.
2. The Brake Pressure Sensor 1 G201 is integrated in ABS Hydraulic Unit N55 and can only be replaced together.
3. Do not disconnect connector (42-pin) before successfully completing self-diagnosis. Switch ignition off before separating connector.
4. Component location: On hydraulic unit in engine compartment, left

1. Removing and installing --> «Hydraulic unit, removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system__hydraulic-unit-removing-and-installing)

13 - Brake system vacuum pump V192

1. Only installed with V6 MPI 3.0L.
2. Removing and installing «Brake system vacuum pump V192 , removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system)

14 - Brake Light Switch F and Brake Pedal Switch F47

1. Removing and installing --> «Brake light switch, removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system__brake-light-switch-removing-and-installing)
2. Can be tested in "Guided Fault Finding" using Vehicle diagnosis, testing and information system VAS 5051

15 - Tandem brake booster

1. Removing and installing --> «Brake booster, removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system__brake-booster-removing-and-installing)

16 - Brake Fluid Level Warning Switch F34

17 - ASR/ESP Button E256

1. Component location: In center console

Scheme 8

Scheme 9

The ABS brake system is divided diagonally (two circuits). The vacuum brake servo unit boosts brakes pneumatically.

Hydraulic unit and control module form one component. Therefore, it is designated as hydraulic control unit.

Malfunction sources are reduced by direct connection of components named. Hydraulic control module is serviced by replacing it.

Bolts that connect individual hydraulic control unit components should not be loosened.

Scheme 10

1 - Brake master cylinder and brake booster

2 - Brake line

1. Brake master cylinder/primary piston circuit to hydraulic control unit

3 - Brake line

1. Brake master cylinder/secondary piston circuit to hydraulic unit

4 - Brake line

1. Hydraulic unit to right front brake caliper

5 - Brake line

1. Hydraulic control unit to left rear brake caliper

6 - Brake line

1. Hydraulic control unit to right rear brake caliper

7 - Brake line

1. Hydraulic unit to left front brake caliper

8 - ABS Hydraulic Unit N55 with ABS Control Module J104

1. With integrated brake pressure sensor
2. Removing and installing --> «Hydraulic unit, removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system__hydraulic-unit-removing-and-installing)

9 - Buffer, Qty. 2

10 - Body long member

11 - Combi-nut, torque specification 10 Nm

12 - ESP bracket

13 - Bolt with rubber bushing, torque specification 10 Nm

1. Integrated securely in assembly

14 - Combi-nut, torque specification 8 Nm

15 - Washer

Hydraulic unit, removing and installing

Special tools, testers and auxiliary items required

Scheme 11

1. Torque wrench V.A.G 1331

Scheme 12

1. Brake pedal actuator V.A.G 1869/2
2. Not shown
3. Repair kit plugs 1H0 698 311 A

Removing

Component location

Scheme 13

Hydraulic unit is located at left of engine compartment.

1. Note or request radio code on vehicles with coded radio if necessary.
2. Disconnect battery. --> «27 - STARTER, GENERATOR, CRUISE CONTROL»(/audi/a6/6-2004-2008/remont/cruise-control-systems/#electrical-equipment)

Scheme 14

1. Remove plenum chamber cover.

Scheme 15

1. Remove coolant reservoir hex head bolt -1-.
2. Disconnect connector from reservoir.

Scheme 16

1. Lay aside reservoir.

Scheme 17

1. Install brake pedal loading device V.A.G 1869/2 between brake pedal and driver seat. Depress brake pedal a minimum of 60 mm.
2. Connect hose of a bleeder bottle to bleeder screws of left front and left rear brake calipers, and open bleeder screws.

Note. Thereby, the pressure in the hydraulic unit is relieved.

1. Close left front and left rear bleeder screws.
2. Do not remove brake pedal loading device V.A.G 1869/2.
3. To protect against escaping brake fluid, place a lint-free rag in the area under control module and hydraulic unit.

Note. Number brake lines.

Scheme 18

1. Completely remove brake lines from hydraulic unit to brake master cylinder.
2. Remove remaining brake lines - arrows - from hydraulic unit.
3. Seal brake lines and threaded bores with sealing plugs from repair kit.
4. Press red securing clip upward

Note. Make sure that no brake fluid gets into the control module connector housing. This could lead to corrosion of the contacts and thereby cause the system to fail. Clean a dirty connector housing thoroughly with compressed air.

1. Release connector at control module - arrow - and remove.

Scheme 19

1. Slide securing bracket in direction of - arrow - and remove connector.

Scheme 20

1. Remove hex head bolts - 1 -.
2. Remove hydraulic control unit.

Installing

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

Note. Do not remove sealing plugs at new hydraulic unit until the corresponding brake line is about to be installed. If the sealing plugs are removed too early, brake fluid can escape. If this occurs, unit may not be sufficiently filled or adequately bled.

Scheme 21

1. Connect lines according to identification

1 - To right front brake caliper

2 - To left rear brake caliper

3 - To right rear brake caliper

4 - To left front brake caliper

5 - To primary piston circuit

6 - To secondary piston circuit

1. Connect connector at hydraulic pump.
2. Clip ABS unit to bracket.

Note. Do not tighten bolts completely. This makes it easier to fasten the individual brake lines to the hydraulic unit.

1. After fastening brake lines, fasten hydraulic unit.
2. Remove brake pedal loading device V.A.G 1869/2.
3. Bleed brake system --> «Bleeding braking system»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system) .
4. Code ABS Control Module J104. Code control module using VAS 5051 via "Guided Fault Finding" function.

1. If control module is replaced, select "Replace" function for respective control module in "Guided Fault Finding".

For this, use Vehicle diagnostic, test and information system VAS 5051.

1. After fastening brake lines to hydraulic unit, perform output check diagnosis. Vehicle diagnostic, test and information system VAS 5051

Note. By performing the output check diagnosis, it can be determined if the line connections were interchanged.

Tightening torques

Scheme 22

1 - ABS wheel speed sensor

1. Before inserting sensor, clean inner surface of mounting hole and coat with Polycarbamide grease G 000 650
2. Replacing «Speed sensor on front axle, removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system__speed-sensor-on-front-axle-removing)

2 - Hex socket head bolt, 18 Nm

3 - Drive axle

4 - Wheel hub with wheel bearing

5 - Socket head bolt

1. Replace after each removal --> «40 - FRONT SUSPENSION»(/audi/a6/6-2004-2008/remont/axle-shafts/#suspension-wheels-steering) Drive shaft, servicing.

Speed sensor on front axle, removing and installing

Special tools, testers and auxiliary items required

Scheme 23

1. Torque wrench V.A.G 1410

Removing

1. Raise vehicle.

Scheme 24

1. Separate speed sensor and speed sensor wiring connector - 1 -.
2. Remove bolt - 2 - from wheel bearing housing.
3. Remove ABS speed sensor from wheel bearing housing.

Installing

1. Before inserting speed sensor, clean hole inner surface and coat speed sensor all-round with Polycarbamide grease G 000 650
2. Insert wheel speed sensor in hole of wheel bearing housing and tighten bolt.
3. Connect speed sensor to speed sensor wiring.

Scheme 25

1 - Socket head bolt

1. Replace after each removal --> «42 - REAR SUSPENSION»(/audi/a6/6-2004-2008/remont/axle-shafts/#suspension-wheels-steering) ; Rear drive shaft, servicing.

2 - Wheel bearing/hub unit

1. The ABS sensor ring is installed in wheel bearing

3 - ABS wheel speed sensor

1. Before inserting sensor, clean inner surface of mounting hole and coat with Polycarbamide grease G 000 650
2. Replacing «Speed sensor on rear axle, removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system__speed-sensor-on-rear-axle-removing)

4 - Hex socket head bolt, 18 Nm

5 - Sensor cable/vehicle side

1. For speed sensor harness

6 - Drive axle

Speed sensor on rear axle, removing and installing

Removing

1. Raise vehicle.

Scheme 26

1. Separate speed sensor - 1 - and speed sensor wiring connector.

Scheme 27

1. Remove bolt - 1 - from wheel bearing housing.
2. Remove ABS speed sensor from wheel bearing housing.

Installing

1. Before inserting speed sensor, clean hole inner surface and coat speed sensor all-round with Polycarbamide grease G 000 650
2. Insert speed sensor into hole in wheel bearing housing and tighten bolt together with retainer for speed sensor harness to 10 Nm.
3. Connect speed sensor to speed sensor wiring.

Brake light switch, removing and installing

Note. Remove brake light switch to adjust. To ensure sufficient secure seating and definite adjustment, the brake light switch may only be installed once.

Removing

1. Separate electrical connection.
2. Remove brake light switch by rotating it 45° toward left.

Installing

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

Scheme 28

1. Pull out plunger of brake light switch completely - arrow -.
2. Insert switch with tabs - 1 - and - 2 - in designated retainers in assembly opening.
3. Remove driver side storage tray: --> «68 - INTERIOR EQUIPMENT»(/audi/a6/6-2004-2008/remont/gauges-instrument-panels/#body-interior)

Note. The brake pedal must not be actuated during installation. When installing brake switch, plunger adjusts itself automatically.

Scheme 29

1. Guide switch through mounting hole, press against pedal and secure by turning 45° to right.

After adjusting the brake light switch check whether the brake pedal is on end stop (rest position).

ESP Sensor Unit G419 , removing and installing

The ESP Sensor Unit G419 is located on front tunnel under air conditioner.

Special tools, testers and auxiliary items required

1. Torque wrench V.A.G 1410

Removing

1. Remove center console extension. --> «68 - INTERIOR EQUIPMENT»(/audi/a6/6-2004-2008/remont/gauges-instrument-panels/#body-interior)

Scheme 30

1. Remove connector - 1 - from ESP Sensor Unit G419.
2. Arrow - points in direction of travel

Scheme 31

1. Remove two mounting bolts - arrows -.
2. Remove ESP Sensor Unit G419 - 1 -.

Installing

Scheme 32

1. Installation is in reverse order of removal.

When installing ESP Sensor Unit G419 make sure it is correctly seated in its mounting and is free of stress.

Do not use securing bolts to forcibly position ESP Sensor Unit G419.

1. Tighten bolts to 10 Nm.
2. If control module is replaced, select "Replace" function for respective control module in "Guided Fault Finding".

For this, use Vehicle diagnostic, test and information system VAS 5051.

Steering angle sensor G85 , removing and installing

The Steering angle sensor G85 is located between steering wheel and steering column switch.

Removing and installing

1. Remove coil ring with slip ring --> «69 - PASSENGER PROTECTION - AIRBAGS, SEAT BELTS»(/audi/a6/6-2004-2008/remont/gauges-instrument-panels/#body-interior)

> 48 - STEERING ; Vehicle diagnostic, test and information system VAS 5051

1. Then the Steering angle sensor G85 zero adjustment must be performed.
2. Connect Vehicle Diagnosis, Testing, and Information System VAS 5051 and select "Functions/Component selection" using Go to button.
3. Then select replace Steering Angle Sensor G85 under "Function" --> «Vehicle Diagnostic, Testing and Information System VAS 5051 , connecting and selecting function»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system) .

Parking Brake Contact Switch F321 , removing and installing

Removing

1. Remove rear center console. --> «68 - INTERIOR EQUIPMENT»(/audi/a6/6-2004-2008/remont/gauges-instrument-panels/#body-interior)
2. Remove Climatronic Control Module J255. --> «87 - AIR CONDITIONING»(/audi/a6/6-2004-2008/remont/ac-compressor/#heating-air-conditioning)
3. Remove Parking Brake Contact Switch F321. --> «96 - LIGHTS, SWITCHES - INTERIOR, ANTI-THEFT»(/audi/a6/6-2004-2008/remont/cruise-control-systems/#electrical-equipment)

Installing

1. Installation is in reverse order of removal.

Left Front Brake Pressure Sensor G518 and Right Front Brake Pressure Sensor G519 , removing and installing

Removing

1. Raise vehicle.

Note. The Brake Pressure Sensor 1 G201 distributors are located on the long member, accessible from the sides over the tie rods.

1. Remove wheels.

Scheme 33

1. Remove nut - 1 - and fold cover away to side.
2. Unclip wiring harness.
3. Plastic housing cover, opening

Scheme 34

1. Remove connector - 1 -.
2. To protect against escaping brake fluid, place sufficient lint-free cloths in area.

Scheme 35

1. Remove brake lines - 2 -. Torque specification 12 Nm.
2. Disconnect Brake Pressure Sensor 1 G201 - 1 - from ACC distributor. Torque specification 12 Nm.

Installing

1. Installation is in reverse order of removal.
2. Bleed brake system --> «Bleeding braking system»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system) .

Front brakes, servicing

Note. Install complete repair kit After replacing brake pads, depress brake pedal several times firmly to properly seat brake pads in their normal operating position. When siphoning brake fluid, always use a bleeder bottle that is used exclusively for brake fluid. Brake fluid is poisonous. NEVER siphon brake fluid with your mouth!

Scheme 36

1 - Brake disc cover

2 - Flange bolt, 10 Nm

1. M6x12

3 - Brake hose

1. Do not remove brake hose when replacing brake pad

4 - Bracket

1. Bolt to brake caliper housing

5 - Hex bolt, 10 Nm

6 - Spring clamp

7 - Brake line

1. Bracket-side torque specification, 17 Nm
2. Brake caliper-side torque specification, 12 Nm
3. Install into brake caliper housing
4. Installed together with brake hose, held against hex nut of brake hose.

1. Make sure that lugs are properly seated in grooves in bracket.

8 - Harness connector

9 - Ribbed bolt, 190 Nm

1. If re-using, clean ribs

10 - Brake carrier

1. Bolt to wheel bearing housing

11 - Brake pads

1. Wear limit --> «Technical data»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system)

Note. The inner surface (with tension spring) is indicated by an arrow. The arrow must point in the rotation direction of the brake rotor when driving forward. If improperly installed, noises could result. Before installing brake pads, clean pad guide surface and coat it with a film of Polycarbamide grease G 052 142 A2 . The backing plate of outer brake pad is equipped with an adhesive film. Peel off protective foil before installing. Left and right front brake wear indicators When wear limit is reached (limit: 3 mm), a warning lamp comes in instrument cluster Must always be replaced together on both sides of axle Removing and installing --> Brake pads, removing and installing Checking brake pad thickness: 405 Different versions

Note. Before installing new brake pads, thoroughly clean the brake calipers of contaminants (grease-free). When doing so, pay particular attention to removing any remaining adhesive foil on outer brake pad contact surfaces.

12 - Retaining spring

1. Before installing brake pads, clean pad guide surface and coat it with a film of Polycarbamide grease G 052 142 A2 .
2. Insert in both holes of brake caliper housing

Note. Retaining spring must be pressed under brake carrier after it is inserted in both holes. If improperly installed, the wear of the outer brake pad cannot be adjusted, thereby increasing brake pedal travel.

13 - Brake disc

1. Wear limit --> «Technical data»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system)
2. Must always be replaced together on both sides of axle
3. Remove brake caliper before removing
4. Thickness --> «Brakes»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system__brakes)

1. Allocation --> «Brakes»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system__brakes)

14 - Bolt

1. Torque specification 5 Nm

15 - Wheel bolts

1. Mounting wheels --> «44 - WHEELS, TIRES, VEHICLE ALIGNMENT»(/audi/a6/6-2004-2008/remont/wheel-tire-system/#wheel-and-tire-guide)

16 - Brake caliper housing

1. To replace brake pads, unfasten from brake carrier
2. Brake caliper, servicing --> «Brake caliper, servicing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system__brake-caliper-servicing)

17 - Guide pins, 30 Nm (18 ft lb)

18 - Concealment cap

1. Remove

Scheme 37

Special tools, testers and auxiliary items required

1. Torque wrench V.A.G 1331
2. Torque wrench V.A.G 1410
3. Brake pedal actuator V.A.G 1869/2
4. Piston resetting tool T10145

1. Torque wrench V.A.G 1332

Removing

1. Raise vehicle.
2. Remove wheels.

Note. When removing, mark brake pads that will be used again. Install in the same position, otherwise braking effect will be uneven! The brake disc is secured with a Phillips head screw.

Scheme 38

1. Remove caps - arrows -.

Scheme 39

1. For vehicles with brake wear pad indicator, disconnect connector - 1 -.
2. Lift fixing latch somewhat on lower part of connector - 2 - and turn 90°.
3. Pull lower part of connector from holder.

Scheme 40

1. Using screwdriver, pry off brake pad retaining spring from brake caliper housing and remove.

Scheme 41

1. Remove both guide pins from brake caliper.
2. Remove brake caliper housing and support it so that the weight of the brake caliper does not stress or damage brake hose.
3. Remove brake pads from brake caliper housing or from brake carrier.

Installing

Scheme 42

1. Press piston back.

Clean brake caliper with mineral spirits exclusively.

Note. Before inserting new brake pads, press the piston back into the cylinder using the piston resetting tool. Before pushing back the piston, siphon some of the brake fluid out of the brake fluid reservoir. Otherwise, especially if reservoir has been topped off, fluid will overflow and cause damage.

Scheme 43

1. Insert brake pad with retaining spring into brake caliper housing (piston).

Note. The inner surface (with tension spring) is indicated by an arrow. The arrow must point in the rotation direction of the brake rotor when driving forward. If improperly installed, noises could result.

1. Remove protective foil from backing plate of outer brake pad.
2. Install outer brake pad on brake carrier.
3. Attach brake caliper housing to brake carrier and fasten guide pins to 25 Nm.
4. Install both protective caps.

1. Install retaining spring in brake caliper housing.

Note. Retaining spring must be pressed under brake carrier after it is inserted in both holes. If improperly installed, the wear of the outer brake pad cannot be adjusted, thereby increasing brake pedal travel. After installing brake pads, depress brake pedal several times firmly to properly seat brake pads in their normal operating position.

1. Check brake fluid level, and fill if necessary.

Note. Install complete repair kit After replacing brake pads, depress brake pedal several times firmly to properly seat brake pads in their normal operating position. When siphoning brake fluid, always use a bleeder bottle that is used exclusively for brake fluid. Brake fluid is poisonous. NEVER siphon brake fluid with your mouth! Check brake caliper for ease of movement by moving it sideways.

Scheme 44

1 - Brake pads

1. Wear limit --> «Technical data»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system)

Note. The inner surface (with tension spring) is equipped with a cable for wear indicator. Must always be replaced together on both sides of axle Before installing brake pads, clean pad guide surface and coat it with a film of Polycarbamide grease G 052 142 A2 . Removing and installing --> Brake pads, removing and installing Checking brake pad thickness: 405 Different versions

Note. Before installing new brake pads, thoroughly clean the brake calipers of contaminants (grease-free). When doing this, pay particular attention to the cleanliness of the brake pad contact surfaces.

2 - Brake carrier

1. Bolt to wheel bearing housing

3 - Ribbed bolt, 196 Nm

1. If re-using, clean the ribs
2. M14x1.5x 38

4 - Bushing

1. Insert in brake caliper housing

5 - Guide pins, 30 Nm (18 ft lb)

6 - Concealment cap

1. Remove
2. Hook in cable for wear indicator

7 - Brake disc

1. Wear limit --> «Technical data»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system)
2. Must always be replaced together on both sides of axle
3. Remove brake caliper before removing
4. Coat contact surfaces between brake disc and wheel hub with Polycarbamide grease G 052 142 A2 . --> «44 - WHEELS, TIRES, VEHICLE ALIGNMENT»(/audi/a6/6-2004-2008/remont/wheel-tire-system/#wheel-and-tire-guide)

1. Allocation --> «Brakes»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system__brakes)
2. Thickness --> «Brakes»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system__brakes)

8 - Wheel bolts

1. Mounting wheels --> «44 - WHEELS, TIRES, VEHICLE ALIGNMENT»(/audi/a6/6-2004-2008/remont/wheel-tire-system/#wheel-and-tire-guide)

9 - Bolt

1. Torque specification 5 Nm

10 - Spring clamp

11 - Brake line connection to brake hose, 12 Nm

12 - Brake line

1. Install into brake caliper housing
2. Installed together with brake hose, held against hex nut of brake hose.
3. Hose must be installed free of twists
4. Make sure that lugs are properly seated in grooves in bracket.

13 - Brake line connection to brake caliper, 17 Nm

14 - Bracket

1. Bolt to brake caliper housing
2. Hook in brake line

15 - Bolt

1. Torque specification 25 Nm

16 - Brake caliper housing

1. Do not allow to hang from brake hose, rather suspend it from body using bundling wire
2. Except for "replacing brake pads" --> «Brake pads, removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system) and "servicing front brake caliper" , no other repairs should be performed on brake caliper
3. Hose must be installed free of twists

17 - Retaining spring

1. Observe correct installed position.

Note. After hooking into both studs, the retaining spring must be pressed under the brake carrier. If improperly installed, the wear of the outer brake pad cannot be adjusted, thereby increasing brake pedal travel.

Brake pads, removing and installing

Special tools, testers and auxiliary items required

1. Torque wrench V.A.G 1331
2. Torque wrench V.A.G 1410
3. Brake pedal actuator V.A.G 1869/2
4. Piston resetting tool T10145

1. Torque wrench V.A.G 1332

Removing

Note. When removing, mark brake pads that will be used again. Install in the same position, otherwise braking effect will be uneven! The brake disc is secured with a Phillips head screw.

1. Raise vehicle.
2. Remove wheels.
3. The brake disc is secured with a bolt - 1 -.

Scheme 45

1. To pry off retaining spring, guide a screwdriver between retaining spring and brake pad retaining spring.

Note. The spring is tensioned, keep hands protected.

1. Ensure surface of brake pad retaining spring is not scratched or damaged.

Scheme 46

1. Retainer, see - arrow
2. Using screwdriver, pry off brake pad retaining spring from brake caliper housing and remove.

Scheme 47

1. Disconnect brake wear indicator connector
2. Release connector from retainer using a screwdriver and simultaneously turn connector 90°
3. Pull connector out upward and unhook line

Scheme 48

1. Unhook brake line - arrow - from retainer

Scheme 49

1. Remove - 1 - caps.

Scheme 50

1. Remove both guide pins from brake caliper.
2. Remove brake caliper housing and set aside so that the weight of the brake caliper does not burden or damage the brake hose.
3. Remove brake pads from brake caliper housing or from brake carrier.

Clean brake caliper with mineral spirits exclusively.

Installing

Scheme 51

1. Press piston back.

Note. Before inserting new brake pads, press the piston back into the cylinder using the piston resetting tool. Before pushing back the piston, siphon some of the brake fluid out of the brake fluid reservoir. Otherwise, especially if reservoir has been topped off, fluid will overflow and cause damage.

Scheme 52

1. Set brake pad with retaining spring and wear indicator into brake caliper housing (piston).

Scheme 53

1. Set outer brake pad - 2 - onto brake caliper.

Note. Insert brake pads into brake caliper and mount them together onto brake carrier and brake disc.

1. Attach brake caliper housing to brake carrier and fasten guide pins to 30 Nm.
2. Make sure brake hose is installed free of twists.
3. Install both protective caps.

Scheme 54

1. Insert brake pad retaining spring - arrows - at upper housing retaining spring and at retaining tab...

Scheme 55

1. ...then press lower housing retaining spring by hand and simultaneously in brake pad retaining spring in direction of - arrow -.

Scheme 56

1. Check whether housing retaining spring is engaged correctly in brake pad retaining spring and whether upper and lower arm is engaged correctly at brake carrier.
2. Hook in brake line
3. Connect connector for wear indicator and hook line into dust cap and cover.
4. Mounting wheels --> «44 - WHEELS, TIRES, VEHICLE ALIGNMENT»(/audi/a6/6-2004-2008/remont/wheel-tire-system/#wheel-and-tire-guide)

Note. After engaging retaining springs in both studs, the retaining spring must be pressed under the brake carrier. If improperly installed, the wear of the outer brake pad cannot be adjusted, thereby increasing brake pedal travel. After installing brake pads, depress brake pedal several times firmly to properly seat brake pads in their normal operating position.

1. Check brake fluid level, and fill if necessary.

Note. Always install complete repair kit After replacing brake pads, depress brake pedal firmly several times with vehicle stationary so that the brake pads are properly seated in their normal operating position. When siphoning brake fluid, always use a bleeder bottle that is used exclusively for brake fluid. Brake fluid is poisonous. NEVER siphon brake fluid with your mouth! Check brake caliper for ease of movement by moving it sideways.

Scheme 57

1 - Brake pads

1. Wear limit --> «Technical data»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system)

Note. The inner surface (with tension spring) is equipped with a cable for wear indicator. The backing plate of the outer brake pad is equipped with an adhesive film. Peel off protective foil before installing. Before installing brake pads, clean pad guide surface and coat it with a film of Polycarbamide grease . Different versions Must always be replaced together on both sides of axle Removing and installing --> Brake pads, removing and installing Checking brake pad thickness: 4E

Note. Before installing new brake pads, thoroughly clean the brake calipers of contaminants (grease-free). When doing so, pay particular attention to removing any remaining adhesive foil on outer brake pad contact surfaces.

2 - Brake carrier

1. Bolt to wheel bearing housing

3 - Ribbed bolt

1. Torque specification, 190 Nm
2. If re-using, clean the ribs
3. M14x1.5x 38

4 - Bushing

1. Insert in brake caliper housing

5 - Guide pins

Torque specification, 30 Nm

6 - Concealment cap

1. Remove
2. Hook in cable for wear indicator

7 - Brake disc

1. Wear limit --> «Technical data»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system)
2. Must always be replaced together on both sides of axle
3. Remove brake caliper before removing
4. Coat contact surfaces between brake disc and wheel hub with polycarbamide grease G 052 142 A2.

8 - Wheel bolts

1. Mount wheels and Tires Guide

9 - Brake line connection to brake hose

1. Torque specification, 12 Nm

10 - Brake line

1. Install into brake caliper housing
2. Installed together with brake hose, held against hex nut of brake hose.
3. Hose must be installed free of twists
4. Make sure that lugs are properly seated in grooves in bracket.

11 - Brake line connection to brake caliper

1. Torque specification, 19 Nm

12 - Bracket

1. Bolt to brake caliper housing
2. Hook in brake line

13 - Bolt M 8x16

1. Torque specification 25 Nm

14 - Brake caliper housing

1. When doing work, do not allow to hang from brake hose, rather suspend it from body using bundling wire
2. Except for "replacing brake pads" --> «Brake pads, removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system) and "servicing front brake caliper" , no other repairs should be performed on brake caliper
3. Install hose so it is not twisted

15 - Retaining spring

1. Observe correct installed position.

Note. After hooking into both studs, the retaining spring must be pressed under the brake carrier. If improperly installed, the wear of the outer brake pad cannot be adjusted, thereby increasing brake pedal travel.

Removing

Note. When removing, mark brake pads that will be used again. Install in the same position, otherwise braking effect will be uneven! Observe the direction of rotation when installing brake disc arrow on brake disc and installed location left or right.

1. Raise vehicle.
2. Remove wheels.

Scheme 58

1. Secure brake disc using a wheel bolt - arrow -.

Scheme 59

1. Using screwdriver, pry off brake pad retaining spring from brake caliper housing and remove.

Note. Spring is tensioned, protect with a glove or cloth.

Scheme 60

1. Disconnect brake wear indicator connector - arrow - , see illustration.

Scheme 61

1. Release connector from retainer using a screwdriver and simultaneously turn connector 90°
2. Pull connector out upward and unhook line

Scheme 62

1. Unhook brake line from retainer

Scheme 63

1. Remove caps - 1 -.

Scheme 64

1. Remove both guide pins from brake caliper.
2. Remove brake caliper housing and set aside so that the weight of the brake caliper does not burden or damage brake hose.
3. Remove brake pads from brake caliper housing or from brake carrier.

Note. The brake pad with wear indicator sits inside. Brake carrier must be removed to replace brake pads.

Clean brake caliper with mineral spirits exclusively.

Installing

Scheme 65

1. Press both pistons back.

Note. Press piston back into caliper housing using resetting tool before inserting new brake pads. Before pushing back the piston, siphon some of the brake fluid out of the brake fluid reservoir. Otherwise, especially if reservoir has been topped off, fluid will overflow and cause damage.

Scheme 66

1. Set brake pad with retaining spring and wear indicator into brake caliper housing (piston).

1. Set outer brake pad - 2 - onto brake caliper.

Note. Insert brake pads into brake caliper and mount them together onto brake carrier and brake disc.

1. Attach brake caliper housing to brake carrier and fasten guide pins to 30 Nm.
2. Install both protective caps.
3. Make sure brake hose is installed free of twists.
4. Install retaining spring in brake caliper housing.

1. Hook in brake line
2. Connect the connector for wear indicator and hook line into dust cap and cover.
3. Install wheels --> «44 - WHEELS, TIRES, VEHICLE ALIGNMENT»(/audi/a6/6-2004-2008/remont/wheel-tire-system/#wheel-and-tire-guide)

Note. After hooking into both studs, the retaining spring must be pressed under the brake carrier. If improperly installed, the wear of the outer brake pad cannot be adjusted, thereby increasing brake pedal travel. After installing brake pads, depress brake pedal several times firmly to properly seat brake pads in their normal operating position.

1. Check brake fluid level, and fill if necessary.

Rear brake, servicing

Rear wheel brake with automatic adjustment

Note. Install complete repair kit

Scheme 67

1 - Self-locking bolt (Torx 30), tightening torque, 12 Nm

2 - Electromechanical parking brake actuator

1. Electromechanical parking brake control module, removing and installing --> «Electro-Mechanical Parking Brake Control Module J540 , removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system__electro-mechanical-parking-brake-control-module-j540)
2. Actuator, removing and installing --> «Electromechanical parking brake actuator, removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system__electromechanical-parking-brake-actuator-removing-and)

3 - Sealing ring

1. Always replace

4 - Self-locking bolt, 35 Nm

1. Always replace
2. When loosening and tightening, counter-hold at guide pin

5 - Spacer

6 - Brake hose

1. To brake caliper, tightening torque 12 Nm
2. Do not disconnect brake line when changing brake pads
3. Ensure retaining tabs are seated correctly in bracket.
4. Install hose without twisting

7 - Brake caliper housing

1. Do not remove brake hose when replacing brake pad
2. Brake caliper, servicing --> «Rear brake caliper piston, removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system)
3. It is possible to install brake carrier with brake caliper

8 - Brake carrier with guide pins and protective cap

1. Supplied as pre-assembled replacement part with sufficient grease on guide pins
2. If protective caps or guide pins are damaged, install repair kit. Use grease packet supplied to lubricate guide pins
3. It is possible to install brake carrier with brake caliper

9 - Brake pads

1. Wear limit --> «Technical data»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system)
2. Must always be replaced together on both sides of axle
3. Removing and installing --> «Brake pads, removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system)
4. Checking brake pad thickness: 405

1. It is possible to install brake carrier with brake caliper

10 - Anti-rattle spring

1. Always replace when pads are replaced

11 - Wheel bolts

1. Mounting wheels --> «44 - WHEELS, TIRES, VEHICLE ALIGNMENT»(/audi/a6/6-2004-2008/remont/wheel-tire-system/#wheel-and-tire-guide)

12 - Phillips-head bolt

1. Torque specification 5 Nm

13 - Brake disc

1. Wear limit --> «Technical data»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system)
2. Must always be replaced together on both sides of axle
3. To remove brake discs on 16" brake systems, brake carrier must be removed.
4. Remove brake caliper before removing

1. Brake disc allocation --> «Brakes»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system__brakes)

14 - Hex bolts, 10 Nm

15 - Brake shield

16 - Ribbed bolts

1. M 12 x 1.5 x 60
2. Always replace
3. Lower connection: To tighten lower connection, adjust Torque Wrench V.A.G 1332 to 115 Nm. This tightening torque only applies in conjunction with Socket T40065 for left side and Socket T40066 for right side.

17 - Ribbed bolts

1. M 12 x 1.5 x 60
2. Always replace
3. Upper connection: Torque specification 140 Nm.

Scheme 68

Special tools, testers and auxiliary items required

1. Torque wrench V.A.G 1331
2. Torque wrench V.A.G 1332
3. Vehicle diagnostic, test and information system VAS 5051
4. Socket T40065

1. Socket T40066

Removing

Note. When removing, mark brake pads that will be used again. Install in the same position, otherwise braking effect will be uneven! Operating the electromechanical parking brake again after a long drive is recommended. Brake pad play is automatically adjusted every 1000 km if the EPB is not operated in this distance. The brake disc is secured with a Phillips head bolt.

1. Raise vehicle.
2. Remove wheels.

Scheme 69

1. With ignition off, connect Vehicle Diagnosis, Testing and Information System VAS 5051 to 16-pin diagnostic connector on vehicle and select parking brake with "Address word" 53.

Note. Ignition on Release parking brake Coding check and reported if necessary. DTC memory interrogated, errors shown corrected and DTC memory erased.

Scheme 70

Shown on VAS 5051 display

1. Select function "53 - Parking brake".
2. Select function "04 - Basic setting".
3. Select function "10 to code after replacing control module".

Scheme 71

Shown on VAS 5051 display

1. The request to enter a display group number appears in display field - 1 -.
2. An entry keypad is shown in display field - 2 -.

When installing new or old brake pads

1. Using entry keypad, enter in display field - 2 - the "7" for "Display group number one and confirm by pressing " Q button. (Reset pistons)
2. To exit entry template, press green Arrow button at lower left.

Note. Ignition off The brake disc is secured with a Phillips head bolt - 1 -.

Scheme 72

1. Remove tires

Scheme 73

1. Remove attachment bolts from brake caliper housing, to do so counter-hold guide pins.

Note. Actuator or brake system connector must not be disconnected. (otherwise, a fault will be saved) Do not pull on brake hose or electrical wiring.

1. Remove brake caliper sideways or hang on body.
2. Remove brake pads
3. Remove guide clamps
4. Press brake pistons back by hand.

Note. To remove brake discs on 16" brake systems, brake carrier must be removed. Check brake discs, replace if necessary.

Remove brake carrier

Scheme 74

1. To remove brake carrier lower connection, use Socket T40065 for the left side and Socket T40066 for the right side.

Installing

Clean brake caliper with mineral spirits exclusively.

Scheme 75

1. Insert brake pad retaining springs

Scheme 76

1. Insert brake pads.

Scheme 77

1. Make sure brake pads are located correctly in anti-rattle springs - arrows -.

Note. The next step only applies to vehicles on which the brake carrier must be disassembled for removal.

1. To install lower connection, use Socket T40065 or Socket T40066.

1. Secure brake caliper housing using new self-locking bolts.

Note. The repair kit includes four self-locking hex bolts which must be installed in all cases.

Shown on VAS 5051 display

1. The request to enter a display group number appears in display field - 1 -.
2. An entry keypad is shown in display field - 2 -.

1. Using entry keypad, enter in display field - 2 - the "6" for "Display group number one and confirm by pressing " Q button. (guide pistons together)
2. To exit entry template, press green Arrow button at lower left.
3. Mounting wheels --> «44 - WHEELS, TIRES, VEHICLE ALIGNMENT»(/audi/a6/6-2004-2008/remont/wheel-tire-system/#wheel-and-tire-guide)
4. Check brake fluid level, and fill if necessary.

Brake pedal (manual transmission), assembly overview

1. Lubricate all bearing and contact surfaces with lubricant part no. Lubricant G 000 450 02 .

Scheme 78

1 - Mounting bracket for pedal assembly

1. Manual transmission illustration

2 - Pin

3 - Securing clip (spring steel)

4 - Torx flange bolt, 10 Nm

5 - Brake pedal

1. Removing and installing --> «Brake pedal, removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system__brake-pedal-removing-and-installing)

6 - Ball socket formed in mount

7 - Wheel hub support

1. For ball head of brake servo push rod

8 - Pressure or over-center spring

1. When installing, spring mount to pedal support, black spring mount to clutch pedal

9 - Bushing

10 - Clutch lever stop

1. Different stops
2. Black: 2.4L gasoline engines (140 mm)
3. White: other engines (150 mm)

11 - Torx flange bolt, 10 Nm

12 - Clutch master cylinder

13 - Clutch pedal

14 - Securing clip (spring steel)

15 - Securing clip (spring steel)

16 - Torx flange bolt, 10 Nm

17 - Clutch sensor bracket

18 - Pin

Brake pedal, removing and installing

Special tools, testers and auxiliary items required

1. Torque wrench V.A.G 1410

Removing

1. Remove trim on drivers side. --> «68 - INTERIOR EQUIPMENT»(/audi/a6/6-2004-2008/remont/gauges-instrument-panels/#body-interior)
2. Remove brake light switch --> «Brake light switch, removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system__brake-light-switch-removing-and-installing) .
3. Disconnect brake pedal from brake booster
4. Remove Torx flange bolt - 3 -.

Scheme 79

1. Loosen retainer - 1 - on right side and remove pins - 5 -.
2. Remove brake pedal.

Installing

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

Joining brake pedal to brake booster

1. Hold ball head of push rod in front of mounting and push brake pedal in direction of brake booster, so the ball head locates audibly.
2. Adjust brake light switch/brake pedal switch --> «Brake light switch, removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system__brake-light-switch-removing-and-installing) .

Brake pedal (automatic transmission), assembly overview

1. Lubricate all bearing and contact surfaces with lubricant part no. Lubricant G 000 450 02 .

Scheme 80

1 - Mounting bracket for pedal assembly

1. Illustration for automatic transmission

2 - Locking washer

3 - Pin

4 - Brake pedal

1. Removing and installing --> «Brake pedal, removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system__brake-pedal-removing-and-installing)

5 - Ball socket in mount

6 - Wheel hub support

1. For ball head of brake servo push rod

7 - Torx flange bolt, 10 Nm

1. Only tighten bolts when securing clips are in place.

8 - Locking washer

9 - Plug

1. Heavy coating in direction of bulkhead

Mounting bracket, removing and installing

Special tools, testers and auxiliary items required

1. Torque wrench V.A.G 1410

1. Torque wrench V.A.G 1331

Removing

1. Remove trim on drivers side. --> «68 - INTERIOR EQUIPMENT»(/audi/a6/6-2004-2008/remont/gauges-instrument-panels/#body-interior)
2. Move adjustable steering column all the way back (opposite direction of travel)

Scheme 81

1. Disconnect accelerator module connector - 1 -.

Scheme 82

1. Disconnect brake light switch - 2 - and remove --> «Brake light switch, removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system__brake-light-switch-removing-and-installing) .
2. Disconnect brake pedal from brake booster

Scheme 83

1. Disconnect connector - 1 - on Clutch Pedal Switch F36.

Scheme 84

1. Disconnect connector - 1 - for Clutch Pedal Switch F194.

1. Remove multi-point socket head bolts - 1 -.

Scheme 85

1. Remove multi-point socket head bolts - 1 - and - 3

Allocation of multi-point socket head bolts , tightening torque 25 Nm.

1. Remove tower brace - 2 -.

Note. Do not remove brake fluid reservoir.

Scheme 86

1. Remove brake fluid reservoir locking bolt - 1 -.
2. Disconnect connector - 2

Scheme 87

1. Press reservoir to side and remove fasteners - 1 -.

Scheme 88

1. Press reservoir to side and remove fasteners - 1 -.

Note. Only affects vehicles with manual transmission.

Scheme 89

1. Remove hex socket head bolt - 1 - , tightening torque 25 Nm.
2. Remove mounting bracket.

Remove gas pedal

Installing

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

1. First thread pins into mounting bracket and attach brake booster.

1. Then install multi-point socket head bolts - 1

Clip brake pedal together with brake booster

1. Hold ball head of push rod in front of mounting and push brake pedal in direction of brake booster, so the ball head locates audibly.
2. Adjust brake light switch/brake pedal switch --> «Brake light switch, removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system__brake-light-switch-removing-and-installing) .

Scheme 90

1 - Parking Brake Contact Switch F321

1. Pull --> Close button
2. Press --> Open button
3. Component location: in center console
4. Removing and installing --> «Parking Brake Contact Switch F321 , removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system__parking-brake-contact-switch-f321)

2 - LED (light emitting diode) display for closed parking brake

3 - EPB system malfunction indicator (yellow)

1. If parking brake malfunctions, a yellow symbol and the brake! appears in instrument cluster display.

4 - Electromechanical parking brake

1. Display for attained tension and dynamic deceleration
2. Indicator light comes on when parking brake is closed and ignition is on.
3. After switching off ignition, indicator light stays on for about 30 seconds.
4. If parking brake is closed with ignition off, indicator light comes on for about 30 seconds.

1. The indicator light must go out when parking brake is released.
2. If indicator light blinks continuously after parking brake is closed, braking force is not sufficient to secure vehicle against rolling. Observe the following
3. If incline is too large to switch off, the Vehicle incline too large also appears.
4. If parking brake malfunctions, a yellow symbol and the brake! appears in the instrument cluster display.

5 - Left Parking Brake Motor V282

1. Removing and installing --> «Electromechanical parking brake (EPB), rear brake caliper»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system)
2. Electromechanical parking brake control module, removing and installing --> «Electro-Mechanical Parking Brake Control Module J540 , removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system__electro-mechanical-parking-brake-control-module-j540)
3. Electromechanical parking brake actuator, removing and installing --> «Electromechanical parking brake actuator, removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system__electromechanical-parking-brake-actuator-removing-and)

6 - Electro-Mechanical Parking Brake Control Module J540

1. Component location: In right rear side panel, below tool set
2. Removing and installing --> «Hydraulic unit, removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system__hydraulic-unit-removing-and-installing)

7 - Right Parking Brake Motor V283

1. Removing and installing --> «Rear brake caliper piston, removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system)

8 - Acoustic signal

1. Warning when operating while driving
2. Warning when malfunction in system is detected

Electro-Mechanical Parking Brake Control Module J540 , removing and installing

Special tools, testers and auxiliary items required

1. Torque wrench V.A.G 1410

Removing

1. Remove right rear side trim in luggage compartment --> «70 - INTERIOR TRIM»(/audi/a6/6-2004-2008/remont/gauges-instrument-panels/#body-interior)

Scheme 91

1. Remove nuts - 1 - , tightening torque 10 Nm
2. Remove EPB control module with plug connector - 2 -.
3. Pull locking slide - a - in direction of arrow - b - and remove connector.

Installing

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

1. If control module is replaced, select "Replace" function for respective control module in "Guided Fault Finding".

Vehicle diagnostic, test and information system VAS 5051

Electromechanical parking brake actuator, removing and installing

Special tools, testers and auxiliary items required

1. Torque wrench V.A.G 1331

1. Vehicle diagnostic, test and information system VAS 5051

Removing

Note. Ignition on Release parking brake Coding check and reported if necessary. DTC memory interrogated, errors shown corrected and DTC memory erased. Ignition off

1. Raise vehicle.
2. Remove wheels.

Note. Ignition must be switched off for at least 30 seconds when disconnecting connector! Clean entire area around connector and actuator/brake caliper. Disconnect actuator connector - 1 -.

Scheme 92

1. Remove both actuator bolts (Torx 30) - 1 -.

Scheme 93

1. Remove actuator in direction of - arrow

Scheme 94

1. Remove sealing ring with a suitable tool.

Ensure ring groove of the seal and contact surface of parking brake actuator do not become damaged.

Note. Do not use any tools with sharp edges.

1. Clean ring groove and contact surfaces if dirty. Only use brake cleaner

Installing

1. Install new seal
2. Turn brake caliper adjuster screw back a bit.

Note. This makes it easier to install the actuator.

Scheme 95

1. Item - 1 - position actuator as shown

Note. Ensure seal is seated correctly

Scheme 96

1. Item - 2 - rotate actuator so bolt hole - a - and threads in brake caliper housing - b - are brought into alignment.

Ensure parking brake actuator is seated flush against brake caliper.

Scheme 97

1. Attach both actuator bolts (Torx 30). Torque specification 12 Nm.

Position bolts by hand and screw in a few turns. If threads are damaged, entire brake caliper must be replaced!

Note. Only insert connector by hand to avoid damaging it. Ensure connectors on vehicle side and actuator side are free of dirt and damage.

1. Install connector.
2. Mounting wheels --> «44 - WHEELS, TIRES, VEHICLE ALIGNMENT»(/audi/a6/6-2004-2008/remont/wheel-tire-system/#wheel-and-tire-guide)

After replacing actuator, basic setting 10 must be performed with the vehicle diagnostic tester in the EPB function.

For this, use Vehicle diagnostic, test and information system VAS 5051.

1. Then select basic section 10 under "Function" --> «Vehicle Diagnostic, Testing and Information System VAS 5051 , connecting and selecting function»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system)

Pressure leak test

Special tools, testers and auxiliary items required

Scheme 98

1. Brake pressure gauge 0-250 bar V.A.G 1310A

High and low pressure testing

Before beginning

Check brake system (brake master cylinder, brake hoses, brake lines and brake calipers) for leak and function.

High pressure testing

Scheme 99

1. Remove bleeder screw at one of the front brake calipers. Connect brake pressure gauge V.A.G 1310A and bleed.
2. Install brake pedal loading device between brake pedal and driver seat. Apply pressure to brake pedal until the gauge indicates a pressure of 50 bar. The pressure must not drop by more than 4 bar during test period of 45 seconds. If pressure drop is large, replace hydraulic unit.

Low pressure testing

1. Set brake pedal loading device back far enough that the pressure gauge indicates 6 bar positive pressure.
2. The pressure must not drop by more than 1 bar during a test period of 3 minutes.

If pressure drop is large, replace hydraulic unit.

Brake caliper, servicing

Note. Install complete repair kit when servicing. New brake calipers are filled with brake fluid and are pre-bled. Apply thin coat of assembly paste G 052 150 A2 to brake cylinders, pistons and seals.

Scheme 100

1 - Caps

1. Insert in bushing

2 - Guide pins, 30 Nm (18 ft lb)

3 - Bleed valve, 10 Nm

1. Apply a thin coat of assembly paste G 052 150 A2 to threads before installing.

4 - Protective cap

1. Push onto bleeder valve

5 - Brake caliper housing

6 - Retaining spring

1. Insert with both ends in holes of brake caliper housing

Note. Retaining spring must be pressed under brake carrier after it is inserted in both holes. If improperly installed, the wear of the outer brake pad cannot be adjusted, thereby increasing brake pedal travel.

7 - Bushing

1. Insert in brake caliper housing

8 - Brake carrier

1. Bolt to brake caliper housing

9 - Sealing ring

10 - Pistons

1. First apply thin coat of brake cylinder paste G 052 150 A2 on piston

11 - Protective cap

1. Do not damage when installing piston

Front brake caliper piston, removing and installing

Special tools, testers and auxiliary items required

1. Assembly paste G 052 150 A2

Scheme 101

1. Disassembly wedge 3409

Scheme 102

1. Piston resetting tool T10145

Removing

Scheme 103

1. Force piston from brake caliper housing using compressed air.

Note. Place a wooden board into recess of the caliper housing so it is not damaged.

1. Remove seal.

Scheme 104

1. Use trim removal wedge 3409 for this.

Note. When removing, make sure that surface of cylinder is not damaged.

Installing

1. Insert seal

1. Use trim removal wedge 3409 for this.

Scheme 105

1. Place protective cap with outer sealing lip on piston.
2. The surface of piston and seal must only be cleaned with mineral spirits and then dried.
3. Thinly coat piston and seal with assembly paste G 052 150 A2 before inserting.

Scheme 106

1. Using trim removal wedge 3409 , insert inner sealing lip into cylinder groove.

Note. Hold piston in front of caliper housing for this procedure.

Scheme 107

1. Press piston into brake caliper housing using piston resetting tool T10145.

Note. Outer sealing lip of protective cap will then engage in piston groove.

Note. Install complete repair kit when servicing. Apply thin coat of assembly paste G 052 150 A2 to brake cylinders, pistons and seals.

Scheme 108

1 - Brake carrier

1. Bolt to brake caliper housing

2 - Guide pins, 30 Nm (18 ft lb)

3 - Caps

1. Insert in bushing

4 - Protective cap

1. Push onto bleeder valve

5 - Bleeder valve, 15 Nm

1. Apply a thin coat of assembly paste G 052 150 A2 to threads before installing.

6 - Bushing

1. Insert in brake caliper housing

7 - Brake caliper housing

8 - Retaining spring

1. Observe correct installed position.
2. Hook in at both brake caliper housing studs and at outer brake pad retaining spring.

9 - Protective cap

1. Do not damage when installing piston
2. Coat with Assembly Paste G 052 150 A2

10 - Pistons

1. First apply thin coat of brake cylinder paste G 052 150 A2 on piston

11 - Sealing ring

1. Coat with Assembly Paste G 052 150 A2

Scheme 109

Special tools, testers and auxiliary items required

1. Torque wrench V.A.G 1331
2. Torque wrench V.A.G 1332
3. Piston resetting tool T10145
4. Disassembly wedge 3409

1. Assembly device for protective cap T10146/5
2. Assembly paste G 052 150 A2

Removing

Scheme 110

1. Force piston from brake caliper housing using compressed air.

Note. Place a wooden board into the recess of the caliper housing so it is not damaged.

1. Remove seal.

Scheme 111

1. Use trim removal wedge 3409 for this.

Note. When removing, make sure that surface of cylinder is not damaged.

Installing

1. The surface of the piston and seal must only be cleaned with mineral spirits and then dried.
2. Thinly coat piston and seal with assembly paste G 052 150 A2 before inserting.

Scheme 112

1. Using Trim Removal Wedge 3409 , insert inner seal into groove in brake caliper.

Scheme 113

1. Press in protective cap using special tool - 1 - and - 2 -.
2. Assembly tool for protective caps T10146/1 - 1
3. Piston resetting tool T10145 - 2

Use protective backings

Scheme 114

1. Press protective cap onto brake caliper housing so that it contacts brake caliper housing all around.
2. It should no longer be possible to remove protective cap from brake caliper housing by hand.
3. Thinly coat piston and seal with assembly paste G 052 150 A2 before inserting.

Scheme 115

1. Lift brake piston, as shown, with commercially available extension and ratchet adapter and lightly press against protective cap.

Do not angle piston, to avoid damaging seal sleeve.

1. Blow protective cap on with pressurized air (max. 3 bar). The protective cap will thereby jump over the brake piston.

Use protective backings

1. Press piston into brake caliper housing by hand.

Note. The inner sealing lip of the protective cap slips into the groove on the piston.

Note. Install complete repair kit when servicing. Apply thin coat of Assembly Paste to brake cylinders, pistons and seals .

Scheme 116

1 - Brake carrier

1. Bolt to brake caliper housing

2 - Guide pins

1. Torque specification, 30 Nm

3 - Caps

1. Insert in bushing

4 - Protective cap

1. Push onto bleeder valve

5 - Bleeder valve

1. Torque specification, 10 Nm
2. Apply a thin coat of Lithium Grease to threads before installing .

6 - Bushing

1. Insert in brake caliper housing

7 - Brake caliper housing

8 - Retaining spring

1. Observe correct installed position.
2. Hook in at both brake caliper housing studs and at outer brake pad retaining spring.

9 - Protective cap

1. Do not damage when installing piston
2. Coat with lithium grease

10 - Pistons

1. Apply thin coat of lithium grease to piston beforehand

11 - Sealing ring

1. Coat with Assembly Paste

Special tools, testers and auxiliary items required

1. Disassembly wedge VAS 3409
2. Assembly Paste

Scheme 117

1. Assembly device for protective cap T10146/5
2. Piston Resetting Tool T10145

Removing

1. Force piston from brake caliper housing using compressed air.

Scheme 118

1. Piston resetting tool Piston Resetting Tool T10145 - 1

Note. Place a wooden board into the recess of the caliper housing so it is not damaged.

Scheme 119

1. Remove protective cap from brake caliper, e.g. with Trim Removal Wedge 3409.
2. Remove seal.

Scheme 120

1. Use Trim Removal Wedge 3409 - 2 - for this.
2. Piston Resetting Tool T10145 - 1

Note. When removing make sure that the surface of the cylinder is not damaged.

Installing

1. The surface of the piston and seal must only be cleaned with mineral spirits and then dried.
2. Thinly coat piston and seal with assembly paste before inserting.
3. Insert inner seal in brake caliper groove using trim removal wedge 8.658.86 cm.

Scheme 121

1. Press in protective cap using special tool - 1 - and - 2 -.
2. Assembly tool for protective caps T10146/5 - 1
3. Piston Resetting Tool T10145 - 2

Use protective backings

Scheme 122

1. Press protective cap onto brake caliper housing so that it contacts brake caliper housing - arrow - all around.

Use protective backings

Scheme 123

1. It should no longer be possible to remove protective cap from brake caliper housing by hand.
2. Thinly coat piston and seal with Assembly Paste before inserting.

Scheme 124

1. Lift brake piston, as shown, with commercially available extension and ratchet adapter and lightly press against protective cap.

Do not angle piston, to avoid damaging seal sleeve.

1. Blow protective cap on with pressurized air (max. 3 bar). The protective cap will jump over brake piston.

Use protective backings

Scheme 125

1. Press piston into brake caliper housing by hand.

Note. The inner sealing lip of the protective cap slips into the groove on the piston.

Note. When performing repairs install all of the parts supplied in repair kit. Apply thin coat of assembly paste G 052 150 A2 to brake cylinders, pistons and seals.

Scheme 126

1 - Self-locking bolt, 35 Nm

1. Always replace
2. When loosening and tightening, counter-hold at guide pin

2 - Brake caliper housing with actuator

1. Pre-bleed caliper housing after repairing --> «Bleeding braking system»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system)

3 - Bleeder valve, 10 Nm

4 - Dust cap

1. Push onto bleeder valve

5 - Sealing ring

1. Removing and installing --> «Rear brake caliper piston, removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system)

6 - Pressure nut

1. To operate parking brake

7 - Pistons

1. Removing and installing --> «Rear brake caliper piston, removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system)

8 - Guide pins

1. Grease before pulling on protective cap

9 - Protective cap

1. Pull onto brake carrier and guide pin

10 - Brake carrier with guide pins and protective cap

1. Supplied as pre-assembled replacement part with sufficient grease on guide pins
2. If protective caps or guide pins are damaged, install repair kit. Use supplied grease packet to lubricate guide pins.

11 - Protective cap

1. Removing and installing --> «Rear brake caliper piston, removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system)
2. Pull onto piston with outer sealing lip

Scheme 127

Special tools, testers and auxiliary items required

1. Torque wrench V.A.G 1331
2. Torque wrench V.A.G 1332
3. Piston resetting tool T10145
4. Disassembly wedge 3409

1. Vehicle diagnostic, test and information system VAS 5051

Removing

1. Remove pistons as far as possible from brake caliper

Scheme 128

1. Force piston out of brake caliper housing using compressed air.

Note. When removing, make sure that surface of cylinder is not damaged. Place a wooden board into recess of the caliper housing so it is not damaged.

Scheme 129

1. Remove old seal from brake caliper with Trim Removal Wedge 3409.

Installing

1. Install new seal in brake caliper.

Scheme 130

1. Place new protective cap on brake pistons as shown.

Scheme 131

1. Install pressure nut to dimension - a - 15 mm.

Scheme 132

1. Insert protective cap in brake caliper groove. Use Trim Removal Wedge 3409.
2. Carefully slide brake piston into brake caliper. When doing so move brake piston. Brake piston must be guided over pressure nut, this is only possible in four positions.

Scheme 133

1. After brake piston has been guided onto pressure nut, press it as far as stop into brake caliper.

Note. Ensure pressure nut is not damaged.

Scheme 134

1. Install pressure nut clockwise as far as stop.

Scheme 135

1. Ensure rubber makes contact around brake caliper housing - arrows

Scheme 136

1. Press piston into brake caliper by hand

Note. The inner sealing lip of the protective cap slips into the groove on the piston.

Bleeding braking system

Note. Only use new brake fluid conforming to US-Norm FMVSS 116 DOT 4. Genuine VW/Audi brake fluid conforms to this specification. Do not use any silicone-based fluid. Avoid contaminating brake fluid with particles or lint (e.g. from cleaning cloths). Rinse off spillages, by using plenty of water. Do not work with compressed air and do not move vehicle while the system is open. During the final road test, ensure that an ABS-controlled brake test is performed at least once (pulsation must be felt at the brake pedal). The brake system indicator light blinks when the brake fluid is too low or the ABS system or parking brake is malfunctioning.

Vehicles with Electronic Stabilization Program (ESP), bleeding procedure

Note. To bleed the hydraulic unit, a pressure of at least 2 bar is necessary. Pressure setting must be checked at bleeder device. Only place brake pedal load device on brake system during assembly, then bleed.

Special tools, testers and auxiliary items required

Scheme 137

1. Brake Filler/Bleeder Unit VAS 5234 or
2. Brake filler/bleeder unit suction adapter V.A.G 1869/4

Observe operating instructions for Brake Filler/Bleeder Unit VAS 5234.

1. Connect Brake Filler/Bleeder Unit VAS 5234
2. Open bleeder screws in specified sequence and bleed brake caliper (support with pedal pressure if necessary).

Bleeding sequence for left and right hand drive vehicles

1 - Left front brake caliper

2 - Right front brake caliper

3 - Left rear brake caliper

4 - Right rear brake caliper

1. Bleed until brake fluid escapes with no bubbles and foam.
2. Close bleeder screw.

Brake fluid, changing

Brake fluid, changing

405 Work descriptions; changing brake fluid (every 2 years)

Brake booster/master brake cylinder, assembly overview

Note. Master brake cylinders can no longer be disassembled, servicing is not possible. Use only new brake fluid. Observe information on brake fluid reservoir!

Scheme 138

1 - Brake fluid reservoir

1. Screen in brake fluid reservoir must not be removed.

2 - Sealing cap with seal

3 - Dowel bolt, 10 Nm

4 - Wiring to master cylinder

5 - Tandem brake booster

1. Adjusting ball head «Adjusting ball head»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system)
2. Functional check: With engine switched off, depress brake pedal firmly several times (to deplete vacuum in tool).
3. Depress and hold brake pedal with average foot pressure and start engine. If brake booster is working properly, pedal will be felt to give noticeably under foot (booster assistance becomes effective).
4. With adhesive seal

1. If malfunctioning: replace as complete unit.
2. Removing and installing --> «Brake booster»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system)

6 - Torx flange bolt, 25 Nm

7 - Mounting bracket for pedal assembly

1. Removing and installing --> «Mounting bracket»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system)

8 - Sleeves

9 - Bolts (Torx 45), 23 Nm

10 - Self-locking hex nut, 49 Nm

11 - Brake line, 16 Nm

1. Master brake cylinder/secondary piston circuit to hydraulic unit

12 - Brake line, 16 Nm

1. Master brake cylinder/primary piston circuit to hydraulic control unit

13 - Sealing ring

1. Replace

14 - Dual master brake cylinder

1. Cannot be serviced. Replace as complete unit if malfunctioning.
2. Removing and installing --> «Brake master cylinder»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system)

15 - Sealing plugs

1. Moisten with brake fluid and press into brake fluid reservoir

16 - Vacuum hose with ear hose clamp

1. Insert into brake booster

17 - Sealing plugs

1. Connection for vacuum hose

Note. Use only new brake fluid. Observe information on brake fluid reservoir!

Scheme 139

a = 178.2 mm ± 0.5mm

Note. Surface - 1 - for measuring. When measuring the ball head, it must be set at right angles to the surface of the brake booster. Measure to end of ball head without gasket installed. Each time push rod adjustment in vehicle is changed, brake light switch must be replaced.

Brake master cylinder, removing and installing

Special tools, testers and auxiliary items required

1. Brake Filler/Bleeder Unit VAS 5234 or
2. Brake filler/bleeder unit suction adapter V.A.G 1869/4
3. Repair kit plugs 1H0 698 311 A

1. Remove plenum chamber cover

1. Remove multi-point socket head bolts - 1 - and - 3 - , tightening torque 25 Nm.
2. Remove tower brace - 2 -.

Scheme 140

1. Open brake fluid reservoir.
2. To protect against escaping brake fluid, place a lint-free rag in area under brake master cylinder.

Scheme 141

1. Draw off as much brake fluid as possible from brake fluid reservoir using Brake Charger/Bleeder Unit Suction Adapter V.A.G 1869/4 or Brake Filler/Bleeder Unit VAS 5234.
2. Remove brake fluid reservoir locking bolt - 1 -.

1. Disconnect connector - 2

Note. Protect plenum chamber from escaping brake fluid.

1. Remove brake line and seal off with plugs.
2. To remove reservoir, press locking tab down and at the same time, remove brake fluid reservoir from sealing plugs.

Scheme 142

1. Completely detach brake lines - 1 - and - 2 - from brake master cylinder and hydraulic assembly and remove.

Scheme 143

1. Remove brake master cylinder bolts - 1 -.
2. Carefully take brake master cylinder out of brake booster.

Installing

When installing, observe the following

1. Before installing brake booster, clean plenum chamber of remaining escaping brake fluid.
2. When installing together brake master cylinder and brake booster, make sure that the push rod is correctly located in brake master cylinder.

1. Bleed brake system --> «Bleeding braking system»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system) .

Brake booster, removing and installing

Special tools, testers and auxiliary items required

1. Brake Filler/Bleeder Unit VAS 5234
2. Brake filler/bleeder unit suction adapter V.A.G 1869/4
3. Repair kit plugs 1H0 698 311 A

1. Remove trim on drivers side. --> «68 - INTERIOR EQUIPMENT»(/audi/a6/6-2004-2008/remont/gauges-instrument-panels/#body-interior)
2. Move adjustable steering column all the way back (opposite direction of travel)

1. Disconnect brake light switch - 2 - and remove, see --> «Brake light switch, removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system__brake-light-switch-removing-and-installing) .
2. Disconnect brake pedal from brake booster

1. Remove plenum chamber cover

1. Remove multi-point socket head bolts - 1 - and - 3 - , tightening torque 25 Nm.
2. Remove tower brace - 2 -.
3. Remove wiper arms --> «92 - WINDSHIELD WIPER AND WASHER SYSTEM»(/audi/a6/6-2004-2008/remont/cruise-control-systems/#electrical-equipment)
4. Remove rear plenum chamber cover.

1. Open brake fluid reservoir.
2. To protect against escaping brake fluid, place a lint-free rag in the area under the brake master cylinder.

1. Draw off as much brake fluid as possible from brake fluid reservoir using Brake Charger/Bleeder Unit Suction Adapter V.A.G 1869/4 or Brake Filler/Bleeder Unit VAS 5234.

1. Remove brake fluid reservoir locking bolt - 1 -.
2. Disconnect connector - 2

Note. Protect plenum chamber from escaping brake fluid.

1. Brake line, removing
2. To remove reservoir, press locking tab down and at the same time, remove brake fluid reservoir from sealing plugs.

1. Completely detach brake lines - 1 - and - 2 - from brake master cylinder and hydraulic assembly, seal with plugs and remove.
2. Remove brake booster bolts - 2 -.

1. Remove vacuum line - 3 -.

Note. Ensure no contamination enters vacuum opening.

1. Remove brake booster with brake master cylinder.

Scheme 144

1. Remove brake master cylinder nut - 1 -.
2. Carefully take brake master cylinder out of brake booster.

Installing

When installing, observe the following

1. Before installing brake booster, clean plenum chamber of remaining escaping brake fluid.
2. When installing together the brake master cylinder and brake booster, make sure that the push rod is correctly located in the brake master cylinder.

Joining brake pedal to brake booster

1. Hold ball head of push rod in front of mounting and push brake pedal in direction of brake booster, so the ball head locates audibly.
2. Adjust brake light switch --> «Brake light switch, removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system__brake-light-switch-removing-and-installing) .
3. Bleed brake system --> «Bleeding braking system»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system) .

Scheme 145

1 - 9 Nm

2 - Vacuum pump

1. Removing and installing --> «Vacuum pump, removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system__vacuum-pump-removing-and-installing)

3 - Vacuum hose

1. Secure with hose clamps that match those used in production

4 - 5 Nm

5 - O-Ring

1. Replace

6 - Intake camshaft

7 - O-Ring

1. Replace

8 - O-Ring

1. Replace

Vacuum pump, removing and installing

Removing

Scheme 146

1. Carefully remove engine cover from 4 retaining pins in succession - arrows -.

Scheme 147

1. Remove coolant reservoir - arrow -.
2. Disconnect electrical connector to Engine Coolant Level (ECL) Warning Switch F66 at bottom of coolant reservoir.
3. Lay aside coolant reservoir with coolant hoses - 1 through 3 - connected.

Scheme 148

1. Remove bolt - 1 - and remove vacuum hose with support to vacuum pump.
2. Remove bolts - arrows - and remove vacuum pump.

Installing

Installation is done in reverse order, but observe the following

Note. Replace O-rings.

Scheme 149

1. Position vacuum pump drive so that it engages in groove on camshaft - arrows - when vacuum pump is installed.

Tightening torques

Scheme 150

1 - Buffer

2 - Hex socket head bolt Qty. 2

1. Torque specification 10 Nm

3 - Bracket

4 - Cap nut

1. Torque specification 10 Nm

5 - Threaded pins to body

6 - Buffer

7 - Locking clip

8 - Brake system vacuum pump V192

1. Removing and installing «Brake system vacuum pump V192 , removing and installing»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system)
2. Checking --> «Brake system vacuum pump V192 , checking»(/audi/a6/6-2004-2008/remont/anti-locktraction-control/#brake-system)

9 - Locking clip

10 - Buffer

Special tools, testers and auxiliary items required

1. Torque wrench V.A.G 1410

1. Torque wrench V.A.G 1331

Vacuum pump is not intended to be serviced. In case of complaints, determine cause with help of function or seal test. If there is a malfunction, replace electrical vacuum pump.

Removing

Note. The electrical vacuum pump is located behind the front bumper under the left headlamp.

1. Remove front bumper --> «63 - BUMPERS»(/audi/a6/6-2004-2008/remont/door-locks-anti-theft-systems/#body-exterior)

Scheme 151

1. Press clip - 1 - out of bracket with hand. 2x

Scheme 152

1. Disconnect electrical connector - 1

1. Disconnect vacuum hose from vacuum pump.

Scheme 153

1. Remove electrical vacuum pump upward.

Remove electrical vacuum pump bracket.

Note. To remove bracket, vacuum pump must first be unclipped from bracket.

1. Remove connections - 2 - and - 3 -.

1. Remove motor vacuum reservoir sideways.

Scheme 154

1. Remove connection - 1 -.

Installing

Installation is in reverse order of removal.

Note. Use new clamps when installing vacuum line.

Description and function

Electric vacuum pump is only installed on vehicles with automatic transmission. It is switched on by engine control module depending on intake line pressure.

Vacuum pump has On Board Diagnostic (OBD) properties. Detected faults are stored in engine control module.

Electric vacuum pump function check can only be carried out using OBD with engine off!

Special tools, testers and auxiliary items required

Scheme 155

1. Vehicle diagnosis, testing and information system VAS 5051
2. Diagnostic cable VAS 5051/1 or diagnostic cable VAS 5051/3

Procedure

1. With ignition switched off, connect vehicle diagnostic, test and information system VAS 5051 with diagnostic cable VAS 5051/1 or diagnostic cable VAS 5051/3 to diagnostic connection.

1. Switch on tester - arrow -.

The tester will now require up to 3 minutes to boot up.

1. Switch on ignition.
2. Select operating mode: On display, select "Vehicle On-Board Diagnosis".
3. Select vehicle system: On display, select "01 - Engine electronics".

At upper right of screen, the control module identification and coding are displayed.

1. Select diagnostic function: At this point, all diagnostic functions are available.
2. On display, select "04 - Basic setting".
3. Press buttons 0 , 0 and 8.
4. Confirm input with Q button.

Displayed at bottom of the screen

1. Actuate brake pedal multiple times with consistent force until test activates.

Displayed at bottom of the screen

The brake pedal may no longer be actuated once the test begins.

The brake system vacuum pump V192 supplies brake booster with vacuum. At the same time, the control module performs a diagnosis of the brake booster system.

If pressure within in the brake booster reaches the cut-off threshold by the time that was predetermined by the diagnostic function, the test has been passed.

Displayed at bottom of the screen

1. Using the Goto button, the operating mode can be interrupted or ended.

If pressure within in the brake booster does not reach the cut-off threshold by the time that was predetermined by the diagnostic function, the test has been failed.

Displayed at bottom of the screen

1. Perform "Guided Fault Finding" using vehicle diagnosis, testing and information system VAS 5051.

Brake booster pressure sensor G294 , removing and installing

Removing

Note. Component location: The Brake Booster Pressure Sensor G294 is located in plenum chamber on brake booster.

1. Remove plenum chamber cover
2. Disconnect electrical connector - 1 -.

Scheme 156

1. Remove pressure sensor in direction of - arrow -.

Note. Pressure sensor can also be secured with clips.

Scheme 157

1. Release clips with pliers - 1 -.
2. Carefully pry Brake Booster Pressure Sensor G294 off.

Installing

Installation is in reverse order of removal.

Checking check valve

Valve must allow air to flow in direction of arrow.

Valve must remain closed in opposite direction.

Observe correct installation position!

Line routing

Brakes and brake lines are delivered as ready-to-install replacement parts.

Secure brakes and brake lines at original fastening points when installing.

Lines to hydraulic assembly

1. Items - 1 - through - 4 - hex nuts (M10 and M12 dia. 5 mm brake lines), 12 Nm tightening torque
2. Items - 5 - and - 6 - hex nuts (M14 dia. 8 mm brake lines), 16 Nm tightening torque

Brake hose to brake caliper to front axle

Scheme 158

1. Item - 1 - brake hose, ensure retaining tabs are seated correctly in bracket.
2. Item - 2 - retaining spring
3. Item - 3 - brake line, 17 Nm tightening torque

Scheme 159

1. Item - 1 - brake line, 17 Nm tightening torque
2. Item - 2 - retaining spring
3. Item - 3 - brake hose, ensure retaining tabs are seated correctly in bracket.

Brake line routing in wheel housing to front axle

Scheme 160

1. Item - 1 - brake line, 12 Nm tightening torque
2. Item - 2 - intermediate piece
3. Item - 3 - brake pipe line, 12 Nm tightening torque

Brake line connecting in wheel housing to front axle

Scheme 161

1. Item - 1 - brake hose bracket
2. Item - 2 - brake line, 12 Nm tightening torque

Brake line routing to rear axle

Scheme 162

1. Item - 1 - brake hose, 12 Nm tightening torque
2. Item - 2 - brake hose bracket, ensure retaining tabs are seated correctly in bracket.
3. Item - 3 - retaining spring
4. Item - 4 - brake line, 12 Nm tightening torque

See also:
• 69 - PASSENGER PROTECTION - AIRBAGS, SEAT BELTS
• 27 - STARTER, GENERATOR, CRUISE CONTROL
• 40 - FRONT SUSPENSION
• 87 - AIR CONDITIONING
• 44 - WHEELS, TIRES, VEHICLE ALIGNMENT
• 63 - BUMPERS
• Brake fluid
• Pressure leak test
• High and low pressure testing
• Parking Brake Contact Switch F321 , removing and installing
• ESP Sensor Unit G419 , removing and installing
• Speed sensor on rear axle, removing and installing
• Speed sensor on front axle, removing and installing
• Hydraulic unit, removing and installing
• Brake light switch, removing and installing
• Brake booster, removing and installing
• Brake pads, removing and installing
• Brakes
• Brake caliper, servicing
• Electro-Mechanical Parking Brake Control Module J540 , removing and installing
• Electromechanical parking brake actuator, removing and installing
• Brake pedal, removing and installing
• Vacuum pump, removing and installing