Hydraulic Components - Brake System Audi Q5 I

BRAKES, TESTING FOR LEAKS

Note. The hydraulic brake system must be bled. Only install genuine parts or components approved by Audi in the brake system. The if the brake fluid replacement interval specified by Audi is exceeded, replace the brake fluid. Visually inspect the brake system (master brake cylinder, brake hoses, brake lines, hydraulic unit and brake calipers) for leaks. The hydraulic pump at the hydraulic unit cannot be replaced. Fix leaks and remove dirt on the hydraulic system.

Switch the engine off.

Press the brake pedal until there is no more brake assistance - "pump the brake booster empty". The brake pedal becomes hard.

Press the brake pedal about 20 mm out of the resting position.

Hold the force on the pedal steady for about 20 seconds.

The brake pedal travel must not increase.

Release the brake pedal.

Press firmly on the brake.

Hold the force on the pedal steady for about 20 seconds.

The brake pedal travel must not increase.

The visual inspection of the brake system (master brake cylinder, brake hoses, brake lines, hydraulic unit and brake calipers) must be repeated if the brake pedal sinks down during one of these tests.

Note. The hydraulic pump at the hydraulic unit cannot be replaced.

If no leaks are found, the brake master cylinder is probably has leaks and must be replaced.

BRAKE FLUID, CHANGING

Brake Fluid, Changing

BRAKE SYSTEM, BLEEDING

Note. Only use new brake fluid conforming to US-Norm FMV SS 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 (for example from cleaning cloths). Rinse off spills, 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 a 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.

BLEEDING PROCEDURE

Note. There must be a positive pressure of 2 bar to bleed the hydraulic unit N55. Pressure setting must be checked at bleeder device. Only place brake pedal load device on brake system during assembly, then bleed.

Special tools and workshop equipment required

1. VAS 5234 Brake Charger/Bleeder Unit
2. VAS 5234/1 Adapter

Bleed the Brake System with the Brake Charger/Bleeder Unit VAS 5234 with the Adapter VAS 5234/1

Follow the VAS 5234 operating instructions.

Remove the plenum chamber cover, refer to Removal and Installation .

Raise the vehicle.

Connect the VAS 5234 with adapter VAS 5234/1.

Open the bleeder screws in the specified sequence and bleed (support with pedal pressure if necessary).

Bleeding Sequence

1

Left front brake caliper

2

Right front brake caliper

3

Left rear brake caliper

4

Right rear brake caliper.

Bleed until brake fluid comes out with no bubbles and foam.

Close the bleeder screws.

Lower vehicle.

Install plenum chamber cover, refer to Removal and Installation .

HIGH AND LOW PRESSURE TESTING

Note. The hydraulic brake system must be bled. Only install genuine parts or components approved by Audi in the brake system. The if the brake fluid replacement interval specified by Audi is exceeded, replace the brake fluid. Visually inspect the brake system (master brake cylinder, brake hoses, brake lines, hydraulic unit and brake calipers) for leaks. The hydraulic pump at the hydraulic unit cannot be replaced. Fix leaks and remove dirt on the hydraulic system.

Special tools and workshop equipment required

1. Brake Pressure Gauge 0-250 bar V.A.G 1310A
2. Brake Pedal Actuator V.A.G. 1869/2

Before Beginning

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

High Pressure Testing

Remove bleeder screw at one of the front brake calipers. Connect V.A.G 1310A and bleed.

Scheme 1

Install the V.A.G 1869/2 between the brake pedal and driver seat.

Scheme 2

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 the test period of 45 seconds.

If there is a large decrease in pressure in the brake system (master brake cylinder, brake hoses, brake lines, hydraulic unit and brake calipers), perform a visual inspection.

Note. The hydraulic pump at the hydraulic unit cannot be replaced.

Low Pressure Testing

Push the V.A.G 1869/2 back until the pressure gauge indicates 6 bar positive pressure.

The pressure must not drop by more than 1 bar during a test period of 3 minutes.

If there is a large decrease in pressure in the brake system (master brake cylinder, brake hoses, brake lines, hydraulic unit and brake calipers), perform a visual inspection.

Note. The hydraulic pump at the hydraulic unit cannot be replaced.

BRAKE BOOSTER/BRAKE MASTER CYLINDER, OVERVIEW

Applies to Hybrid Vehicles

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 3

1. 1 - Brake Fluid Reservoir Do not remove the screen in the brake fluid reservoir. Removing and Installing, refer to «BRAKE FLUID RESERVOIR»(/audi/q5/i-2008-2012/remont/brakes-control-systems/#hydraulic-components-brake-system__brake-fluid-reservoir).
2. 2 - Brake Fluid Reservoir Cover Not installed in all vehicles. Removing and Installing, refer to «BRAKE FLUID RESERVOIR COVER»(/audi/q5/i-2008-2012/remont/brakes-control-systems/#hydraulic-components-brake-system__brake-fluid-reservoir-cover) NOTE: The cover is not installed on all vehicles.
3. 3 - Sealing Cap with Seal and Brake Fluid Level Warning Switch -F34
4. 4 - Bolt 5 Nm
5. 5 - Wiring to the Clutch Master Cylinder
6. 6 - Brake Booster Adjusting ball head (Scheme 4) Functionality test: with engine switched off, depress brake pedal firmly several times (to deplete vacuum in the tool). 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). With adhesive seal. If malfunctioning: replace as complete unit. Removing and Installing, refer to «BRAKE BOOSTER»(/audi/q5/i-2008-2012/remont/brakes-control-systems/#hydraulic-components-brake-system__brake-booster).
7. 7 - Pedal Support Bolt 20 Nm
8. 8 - Brake Pedal Removing and Installing, with Manual Transmission, refer to «BRAKE PEDAL, WITH MANUAL TRANSMISSION»(/audi/q5/i-2008-2012/remont/mechanical-hydraulic/#mechanical-components-brake-system__brake-pedal-with-manual-transmission). Removing and Installing, with Automatic Transmission, refer to «BRAKE PEDAL, WITH AUTOMATIC TRANSMISSION»(/audi/q5/i-2008-2012/remont/mechanical-hydraulic/#mechanical-components-brake-system__brake-pedal-with-automatic-transmission).
9. 9 - Brake Lamp Sensor Removing and Installing, refer to «BRAKE LAMP SENSOR»(/audi/q5/i-2008-2012/remont/anti-locktraction-control/#anti-lock-brake-system__brake-lamp-sensor).
10. 10 - Bolt Connects the brake booster to the mounting bracket. 25 Nm
11. 11 - Hex Nut For the brake master cylinder. 49 Nm
12. 12 - Brake Line Brake master cylinder to the hydraulic unit. 14 Nm
13. 13 - Brake Line Brake master cylinder to the hydraulic unit. 14 Nm
14. 14 - Gasket Replace
15. 15 - Brake Master Cylinder Cannot be serviced. Replace as complete unit if malfunctioning. Removing and Installing, refer to «MASTER BRAKE CYLINDER»(/audi/q5/i-2008-2012/remont/brakes-control-systems/#hydraulic-components-brake-system__master-brake-cylinder).
16. 16 - Sealing Plug Moisten with brake fluid and press into brake fluid reservoir.

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

Scheme 4

Left-hand drive vehicles

Right-hand drive vehicles

a = 164.7mm +/- 0.5 mm

Note. Surface -1- for measuring. When measuring, ball head must be arranged at a right angle to surface of brake booster. Measure to end of ball head without gasket installed.

Ball head to the push rod, 30 Nm.

BRAKE CALIPER, FBC, OVERVIEW

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

Scheme 5

1. 1 - Bolt 30 Nm
2. 2 - Cap Insert in brake caliper. Replacing, refer to «PROTECTIVE CAP AND GUIDE PINS, FBC BRAKES»(/audi/q5/i-2008-2012/remont/brakes-control-systems/#hydraulic-components-brake-system__protective-cap-and-guide-pins-fbc) .
3. 3 - Guide Pins Slide through the boot. Replacing, refer to «PROTECTIVE CAP AND GUIDE PINS, FBC BRAKES»(/audi/q5/i-2008-2012/remont/brakes-control-systems/#hydraulic-components-brake-system__protective-cap-and-guide-pins-fbc) .
4. 4 - Cap Install on the bleeder valve.
5. 5 - Bleeder Valve Apply a thin coat of assembly paste G 052 150 A2 to the threads before screwing in. 15 Nm
6. 6 - Brake Caliper Housing
7. 7 - Spring Ensure installation position is correct.
8. 8 - Cap Do not damage when installing piston. Coat with Assembly Paste G 052 150 A2.
9. 9 - Pistons First apply thin coat of brake cylinder paste G 052 150 A2 on piston. Diameter 57 mm.
10. 10 - Seal Coat with assembly paste G 052 150 A2.
11. 11 - Brake Carrier Removing and Installing, refer to «BRAKE CALIPER WITH FRONT BRAKE CARRIER, FBC-60, REMOVING AND INSTALLING»(/audi/q5/i-2008-2012/remont/mechanical-hydraulic/#mechanical-components-brake-system__brake-caliper-with-front-brake-carrier) . The 4 retaining pins for the brake pads on the brake carrier must not be loosened under any circumstances.
12. 12 - Bolt 196 Nm

Scheme 6

1. Brake System Vacuum Pump -V192- Removing and installing, refer to «Brake System Vacuum Pump -V192»(/audi/q5/i-2008-2012/remont/brakes-control-systems/#hydraulic-components-brake-system__brake-system-vacuum-pump-v192) . Checking, refer to «Brake System Vacuum Pump -V192-, CHECKING»(/audi/q5/i-2008-2012/remont/brakes-control-systems/#hydraulic-components-brake-system__brake-system-vacuum-pump-v192-checking) .
2. Nut 9 Nm
3. Check Valve Checking, refer to «CHECK VALVE, CHECKING»(/audi/q5/i-2008-2012/remont/brakes-control-systems/#hydraulic-components-brake-system__check-valve-checking) .
4. Buffer
5. Vacuum Hose
6. Sleeve
7. Bolt 9 Nm
8. Bracket
9. Nut 8 Nm

Note. The brake booster pressure sensor -G294- is installed on the brake booster. Removing and installing, refer to Brake Booster Pressure Sensor -G294

ELECTRONIC PARKING BRAKE REAR CALIPER, OVERVIEW

Note. When servicing, install entire repair kit. Apply thin coat of assembly paste G 052 150 A2 to brake cylinders, pistons and seals.

Scheme 7

1. 1 - Self-Locking Bolt 35 Nm Always replace. Counterhold at the guide pin when loosening and tightening.
2. 2 - Brake Caliper Housing with Actuator
3. 3 - Bleeder Valve 10 Nm
4. 4 - Dust Cap Push onto bleed valve.
5. 5 - Seal Removing and installing, refer to «REAR BRAKE CALIPER PISTON»(/audi/q5/i-2008-2012/remont/brakes-control-systems/#hydraulic-components-brake-system__rear-brake-caliper-piston) .
6. 6 - Pressure Nut To operate parking brake.
7. 7 - Pistons Removing and installing, refer to «REAR BRAKE CALIPER PISTON»(/audi/q5/i-2008-2012/remont/brakes-control-systems/#hydraulic-components-brake-system__rear-brake-caliper-piston) .
8. 8 - Guide Pins Grease before pulling on protective cap. Delivered as a replacement part with sufficient grease. Replacing, refer to «REAR BRAKES GUIDE PINS AND PROTECTIVE CAPS»(/audi/q5/i-2008-2012/remont/brakes-control-systems/#hydraulic-components-brake-system__rear-brakes-guide-pins-and-protective) .
9. 9 - Cap Pull onto the brake carrier and guide pin. Replacing, refer to «REAR BRAKES GUIDE PINS AND PROTECTIVE CAPS»(/audi/q5/i-2008-2012/remont/brakes-control-systems/#hydraulic-components-brake-system__rear-brakes-guide-pins-and-protective) .
10. 10 - Brake Carrier with Guide Pins and Cap Supplied as an assembled replacement part with sufficient grease on guide pins. If protective caps or guide pins are damaged, install repair kit. Use grease packet supplied to lubricate guide pins.
11. 11 - Cap Removing and Installing, refer to «REAR BRAKE CALIPER PISTON»(/audi/q5/i-2008-2012/remont/brakes-control-systems/#hydraulic-components-brake-system__rear-brake-caliper-piston) . Pull onto the piston with the outer sealing lip.

Scheme 8

1. Torx® 30 Bolt (quantity: 2) 9 Nm Remove to remove the pump. NOTE: The pump is not designed to be disassembled.
2. Vacuum Pump
3. Vacuum Hose Secure with hose clamps that match those used in production
4. Bolt 5 Nm NOTE: Installing the bolt depends on the model. Alternatively, secure the vacuum hose with the hose clamp for the vehicle version
5. O-Ring Replace NOTE: Installation of the o-ring depends on the model.
6. O-Ring Replace NOTE: Installation of the o-ring depends on the model.
7. O-Ring Replace NOTE: Installation of the o-ring depends on the model.

FASTENER TIGHTENING SPECIFICATIONS

BRAKE BOOSTER VACUUM SYSTEM, CHECKING

Special tools and workshop equipment required

1. Brake Servo Tester VAS 6721

The following checks will be helpful when performing Fault Finding if there are complaints regarding the brake booster or the so-called hard brake pedal.

The following components are included in the check

1. Brake booster.
2. Seal between the master brake cylinder and the brake booster.
3. Check valve
4. Vacuum hoses and connectors.
5. Vacuum pump (if equipped).

Keep the geographical surrounding in mind when evaluating the measured results. The higher above sea level, the lower the air pressure.

Always observe all test requirements before checking the vacuum system

1. Check all the vacuum hoses for damage (for example, tears or damaged caused by animals) and make sure they are secure.
2. Maintain clean working conditions when working on the vacuum system.
3. Clean the engine compartment before starting, if necessary.

BRAKE SERVO TESTER VAS 6721, CONNECTING

Special tools and workshop equipment required

1. Brake Servo Tester VAS 6721
2. Hand Vacuum Pump VAS 6213

Remove the vacuum hose from the brake booster.

Pressing the brake pedal a few times beforehand makes it easier to remove the vacuum hose.

Connect the VAS 6721 -see following illustrations-.

Scheme 9

Connect the VAS 6721 hose -A- too the vacuum hose and push the adapter -C- into the brake booster.

Scheme 10

VACUUM, CHECKING

Special tools and workshop equipment required

1. Brake Servo Tester VAS 6721
2. Hand Vacuum Pump VAS 6213

Note. The average earth atmospheric air pressure at sea level (N. N.) is 1013 mbar and it decreases dramatically at higher altitudes (approximately 100 mbar every 1000 meters higher) Local and time fluctuations will influence the vacuum. A cold engine, the A/C switched being on and even only the engine idling can negatively influence the vacuum.

Check all the vacuum hoses beforehand for damage (for example, tears or damaged caused by animals) and make sure they are secure.

Connect the VAS 6721. Refer to Brake Servo Tester VAS 6721, CONNECTING .

Open the shut-off valve -A-.

Close the shut-off valves -B+C-.

Scheme 11

Start the warm (above 60° C) engine and press the accelerator pedal one time quickly (engine RPM higher than 2, 000).

Read the measured value displayed.

Normally (see note) the vacuum should be between 600 and 950 mbar (depending on the engine installed).

Check the vacuum system for leaks if the measured value is not reached, even though all requirements (see notes).

Create the vacuum using a VAS 6213 for comparison purposes. Refer to VACUUM, CREATING USING Hand Vacuum Pump VAS 6213 .

Opening the shut-off valve -B- makes it easier to remove the hose connections and the adapter.

LEAK TEST

Special tools and workshop equipment required

1. Brake Servo Tester VAS 6721
2. Hand Vacuum Pump VAS 6213

Note. The average earth atmospheric air pressure at sea level (N. N.) is 1013 mbar and it decreases dramatically at higher altitudes (approximately 100 mbar every 1000 meters higher) Local and time fluctuations will influence the vacuum. A cold engine, the A/C switched being on and even only the engine idling can negatively influence the vacuum.

Check all the vacuum hoses beforehand for damage (for example, tears or damaged caused by animals) and make sure they are secure.

Connect the VAS 6721. Refer to Brake Servo Tester VAS 6721, CONNECTING .

Open the shut-off valve -A-.

Close the shut-off valves -B+C-.

Start the warm (above 60° C) engine and press the accelerator pedal one time quickly (engine RPM higher than 2, 000).

Normally (see note) the vacuum should be between 600 and 950 mbar (depending on the engine installed).

Open the shut-off valve -C- and evacuate the brake booster.

Scheme 12

Turn off the engine.

Read the measured value displayed and write it down.

The vacuum may drop 400 mbar within 12 hours.

If the drop in vacuum is greater, check the....

1. Brake Booster or in the
2. Check Valve, Vacuum Hoses and Connections and Vacuum Pump/Intake Manifold for leaks.

The vacuum will drop considerably within a few seconds if there are large leaks.

Checking the Vacuum Near the Brake Booster

Close the shut-off valve -A- after creating the vacuum to test the brake booster vacuum.

Scheme 13

Vacuum Test Near the Check Valve, Vacuum Hoses and Connections and Vacuum Pump/Intake Manifold

Close the shut-off valve -C- after creating the vacuum to check the VAS 6721 vacuum up to the intake manifold or up to the vacuum pump.

Opening the shut-off valve -B- makes it easier to remove the hose connections and the adapter.

VACUUM, CREATING USING HAND VACUUM PUMP VAS 6213

Special tools and workshop equipment required

1. Hand Vacuum Pump VAS 6213
2. Brake Servo Tester VAS 6721

In certain situations, the vacuum can be created using a VAS 6213 instead of using the engine or a vacuum pump.

Connect the VAS 6213 to the vacuum hose on the connection -B- on the VAS 6721.

Open the shut-off valve -B-.

Create the vacuum using the VAS 6213 until a vacuum between 600 and 950 mbar on the VAS 6721 is displayed.

Perform the tests.

BRAKE SYSTEM VACUUM PUMP -V192-, CHECKING

Special tools and workshop equipment required

1. Hand Vacuum Pump VAS 6213
2. Brake Servo Tester VAS 6721
3. Vehicle Diagnostic Tester

Turn off the ignition and connect the vehicle diagnostic tester to the 16-pin diagnostic connection.

Scheme 14

Note. Switch on the ignition. Coding check and reported if necessary. DTC memory interrogated, errors shown corrected and DTC memory erased.

Start the program in Guided Functions.

CHECK VALVE, CHECKING

Note. The check valve is tightly installed in the vacuum hose. To check it, the vacuum hose must be removed.

Valve must allow air to flow in direction of arrow.

Valve must remain closed in opposite direction.

Observe correct installation position.

The flow direction arrow faces the vacuum pump.

FRONT BRAKE CALIPER PISTON, FBC

Removing

Special tools and workshop equipment required

1. Trim Removal Wedge 3409
2. Piston Resetting Tool T10145
3. Assembly Paste G 052 150 A2

Force piston from brake caliper housing using compressed air.

Scheme 15

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

Remove seal.

Scheme 16

Use the 3409 for this.

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

Installing

The surface of the piston and seal must only be cleaned with mineral spirits and then dried.

Thinly coat piston and seal with assembly paste G 052 150 A2 before inserting.

Insert the inner seal in the brake caliper groove -arrow-.

Scheme 17

Press the protective cap onto the brake caliper housing so that it contacts the brake caliper housing all around.

Scheme 18

It should no longer be possible to remove the protective cap from the brake caliper housing by hand.

Thinly coat piston and seal with assembly paste G 052 150 A2 before inserting.

Press the brake piston lightly on the protective cap.

Do not angle piston, to avoid damaging the seal sleeve.

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

Press the brake pistons into the caliper using T10145.

Scheme 19

Do not angle piston, to avoid damaging the seal sleeve.

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

PROTECTIVE CAP AND GUIDE PINS, FBC BRAKES

The guide pins must be removed if the protective caps are damaged.

Removing

Note. When removing, mark brake pads that will be used again. Install in the same position, otherwise braking effect will be uneven!

Press the retaining spring -7- in the center.

Note. The spring is tensioned, keep hands protected. When removing the spring, make sure it does not scratch the brake caliper or damage the paint.

Remove the retaining spring carefully.

Remove the bolts -1- on the brake caliper.

Remove the brake caliper.

Note. Do not let the brake caliper hang from the brake hose. Secure it to the body with suitable cable ties or wire. Do not support the weight with the brake hose.

Remove the protective cap -2- on the outside from the groove on the guide pin.

Pull the guide pin -3- outward out of the protective cap.

Remove the protective cap from the brake caliper.

Installing

Carefully press the guide pin into the protective cap as far as the first groove.

Insert the protective cap in the brake caliper.

The protective cap must be seated in the center of the brake caliper.

Press the guide pin through the protective cap.

The protective cap must not be seated in both grooves on the guide pin.

Check the movement of the guide pin. Both guide pins must slide.

Install the brake caliper and tighten the bolts -1- to 30 Nm.

Position the retaining spring -7- on the outer brake pad.

Press the retaining spring in the center and insert the center tab of the retaining spring in the hole on the brake caliper.

Note. The spring is tensioned, keep hands protected. When removing the spring, make sure it does not scratch the brake caliper or damage the paint. The retaining spring tab must sit correctly in the hole -arrow- in the brake caliper or it can spring out and the brake pad will not be held in place.

Scheme 20

REAR BRAKE CALIPER PISTON

Special tools and workshop equipment required

1. Torque Wrench 5-50 Nm V.A.G 1331
2. Torque Wrench 40-200 Nm V.A.G 1332
3. Piston Resetting Tool T10145
4. Trim Removal Wedge 3409
5. Vehicle Diagnostic Tester VAS 5051B

Removing

Remove pistons as far as possible from brake caliper.

Force piston out of brake caliper housing using compressed air.

Scheme 21

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

Remove old seal from brake caliper with 3409.

Scheme 22

Installing

Install new seal in brake caliper.

Place new protective cap on brake pistons as shown.

Scheme 23

Install pressure nut to dimension -a- 15 mm.

Scheme 24

Insert protective cap in brake caliper groove. Use 3409 to do so.

Scheme 25

Carefully slide brake piston into brake caliper. Move brake piston when doing so. Brake piston must be guided over pressure nut, this is only possible in four positions.

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

Scheme 26

Note. Make sure that pressure nut is not damaged.

Install the pressure nut clockwise as far as the stop.

Scheme 27

Make sure the rubber makes contact around brake caliper housing -arrows-.

Scheme 28

Press the piston into the brake caliper by hand.

Scheme 29

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

REAR BRAKES GUIDE PINS AND PROTECTIVE CAPS

If protective caps or guide pins are damaged, install repair kit. Use grease packet supplied to lubricate guide pins.

Removing

Remove the bolts -1- on the brake caliper.

Remove the brake caliper.

Note. Do not let the brake caliper hang from the brake hose. Secure it to the body with suitable cable ties or wire. Do not support the weight with the brake hose.

Remove the protective cap -9- from the nut on the brake carrier.

Remove the guide pins -8- from the brake carrier.

Remove the protective cap from the guide pin.

Installing

Grease the guide pin before inserting.

Slide the protective cap over the groove on the guide pin.

Slide the guide pin -8- with the protective cap -9- through the brake carrier.

Press the protective cap over the groove on the brake carrier.

Insert the brake caliper.

Install the bolts -1- and tighten them.

BRAKE FLUID RESERVOIR COVER

Note. Not installed in all vehicles.

The brake fluid reservoir cover has an opening on the left to check the brake fluid level. To prevent damage later, brake fluid must not enter between the brake fluid reservoir cover and the brake fluid reservoir.

Removing

Remove the plenum chamber cover, refer to Removal and Installation .

Remove bolt -4-.

Remove the brake fluid reservoir cover from the vehicle.

Installing

Place the brake fluid reservoir cover over the brake fluid reservoir.

Install the bolt -4- and tighten.

Install plenum chamber cover, refer to Removal and Installation .

BRAKE FLUID RESERVOIR

Special tools and workshop equipment required

1. Brake Charger/Bleeder Unit VAS 5234
2. Adapater VAS 5234/1

Removing

Remove the plenum chamber cover, refer to Removal and Installation .

Disconnect the connector from the brake fluid level warning switch -F34-.

Remove the brake fluid reservoir cover over the brake fluid reservoir, refer to BRAKE FLUID RESERVOIR COVER .

Note. The brake fluid reservoir cover is not installed on all vehicle models.

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 the brake fluid reservoir with the VAS 5234 and VAS 5234/1.

With manual transmissions, remove the clutch hydraulic line -5- from the brake fluid reservoir and seal it.

Pull the lower locking pin out of the brake fluid reservoir.

Remove the brake fluid reservoir from the brake master cylinder.

Installing

Remove the protective cap on the new brake fluid reservoir just before filling it.

Coat the plugs on the brake fluid reservoir with brake fluid.

Insert the brake fluid reservoir in the sealing plugs in the brake master cylinder.

Push the lower locking pin through the brake fluid reservoir.

Connect the electrical connector from the brake fluid level warning switch -F34-.

With manual transmission, connect the clutch hydraulic line -5- to the brake fluid reservoir.

Fill the brake fluid up to the marking.

Bleed the brake system. Refer to BRAKE SYSTEM, BLEEDING .

Install the brake fluid reservoir cover over the brake fluid reservoir.

Note. The brake fluid reservoir cover is not installed on all vehicle models.

Install plenum chamber cover, refer to Removal and Installation .

MASTER BRAKE CYLINDER

Special tools and workshop equipment required

1. Torque Wrench 5-50 Nm V.A.G 1331
2. Adapter VAS 5234/1
3. Brake Charger/Bleeder Unit VAS 5234
4. Sealing plugs repair kit, Part no. 1H0 698 311 A

Applies to Hybrid Vehicles

Removing

Plenum chamber cover, removing, refer to Removal and Installation .

Remove the tower brace, refer to Removal and Installation .

Applies to Hybrid Vehicles

Remove the electrical A/C compressor high voltage cable -P3- from the plenum chamber bulkhead .

Continuation for All Vehicles

Remove the plenum chamber bulkhead, refer to Removal and Installation .

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 the brake fluid reservoir with the VAS 5234.

Remove the brake fluid reservoir, refer to BRAKE FLUID RESERVOIR .

Disconnect brake lines -2- at brake master cylinder and seal brake lines with sealing plugs from repair kit.

Scheme 30

Remove brake master cylinder nuts -3-.

Remove brake master cylinder from brake booster.

Remove the brake master cylinder from the vehicle.

Installing

Install in reverse order of removal.

Note. Use new nuts.

Replace sealing ring between brake master cylinder and brake booster.

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

Press brake pedal down slightly. This makes it easier to guide the push rod into the brake master cylinder.

Install new nuts -3- and tighten. Note torque.

Install brake lines -2- on brake master cylinder. Note torque.

Install the brake fluid reservoir -1-, refer to BRAKE FLUID RESERVOIR .

With manual transmissions, insert the clutch hydraulic line -5- into the brake fluid reservoir.

Fill the brake fluid up to the marking.

Bleed the brake system. Refer to BRAKE SYSTEM, BLEEDING .

Install the plenum chamber bulkhead, refer to Removal and Installation .

Applies to Hybrid Vehicles

Attach the electrical A/C compressor high voltage cable -P3- to the plenum chamber bulkhead .

Continuation for all vehicles

Install the tower brace, refer to Removal and Installation .

Install plenum chamber cover, refer to Removal and Installation .

Perform ESP driving and system test.

BRAKE BOOSTER

Applies to Hybrid Vehicles

Removing

Special tools and workshop equipment required

1. Torque Wrench 5-50 Nm V.A.G 1331
2. Adapter VAS 5234/1
3. Brake Charger/Bleeder Unit VAS 5234
4. Sealing plugs repair kit, Part no. 1H0 698 311 A

Switch the engine off.

Press the brake pedal until there is no more brake assistance - "pump the brake booster empty". The brake pedal becomes hard.

Remove the driver side storage compartment -1 to 3-.

Scheme 31

Disconnect the electrical connector to the footwell vent -C-.

Scheme 32

Remove the footwell vents -A-B-.

Remove the brake lamp sensor, refer to BRAKE LAMP SENSOR .

Disconnect brake pedal from brake booster, refer to BRAKE PEDAL AND BRAKE BOOSTER, DISCONNECTING AND CONNECTING .

Remove the plenum chamber cover, refer to Removal and Installation .

Remove the tower brace, refer to Removal and Installation .

Applies to Hybrid Vehicles

Remove the electrical A/C compressor high voltage cable -P3- from the plenum chamber bulkhead .

Continuation for All Vehicles

Remove the plenum chamber bulkhead, refer to Removal and Installation .

Remove the brake fluid reservoir, refer to BRAKE FLUID RESERVOIR .

Remove the brake master cylinder at the nuts -3-, refer to MASTER BRAKE CYLINDER .

Remove the brake master cylinder from the vehicle.

Place the brake master cylinder so no brake fluid can drain out.

Remove the vacuum line -3- from the brake booster.

Scheme 33

Remove the bolts mounting the brake booster -1- to the mounting bracket.

Remove the brake booster from the vehicle.

Installing

Insert the brake booster in the vehicle.

Make sure the seal is seated correctly.

Install the bolts from the brake booster -1- to the mounting bracket and tighten them.

Press the vacuum line -3- into the brake booster.

Install the brake master cylinder -15-, refer to MASTER BRAKE CYLINDER .

Install the brake fluid reservoir -1-, refer to BRAKE FLUID RESERVOIR .

With manual transmissions, insert the clutch hydraulic line -5- into the brake fluid reservoir.

Fill the brake fluid up to the marking.

Bleed the brake system. Refer to BRAKE SYSTEM, BLEEDING .

Install the plenum chamber bulkhead, refer to Removal and Installation .

Applies to Hybrid Vehicles

Attach the electrical A/C compressor high voltage cable -P3- to the plenum chamber bulkhead .

Continuation for All Vehicles

Install the tower brace, refer to Removal and Installation .

Install plenum chamber cover, refer to Removal and Installation .

Brake Pedal and Brake Booster, Connecting

Hold the push rod ball head in front of the mount and push the brake pedal toward the brake booster, so that the ball head clicks into place.

Install the brake lamp sensor, refer to BRAKE LAMP SENSOR .

Install the footwell vents -A-B-.

Tighten the footwell vent screw -A-.

Connect the connector -C-.

Install the driver side storage compartment -1 to 3-.

BRAKE SYSTEM VACUUM PUMP -V192

It is not possible to service the Brake System Vacuum Pump --. If there is a malfunction, replace Brake System Vacuum Pump --.

Note. The brake system vacuum pump is installed in the front left in the engine compartment next to the ABS hydraulic unit -N55-.

Removing

Disconnect the connector -1- and remove it from the clip on the brake system vacuum pump -- mount.

Scheme 34

Release the vacuum hose -2- and remove it from the brake system vacuum pump --.

Remove the nuts -arrows- and then remove the brake system vacuum pump -- -1- upward.

Scheme 35

Installing

Insert the brake system vacuum pump -- -1- into the mount.

Note. Make sure the vacuum pump fits correctly in the bracket. The vacuum connection faces the direction of travel.

Tighten the brake system vacuum pump -- and the nuts -arrow- in the mount to 8 Nm.

Slide the vacuum hose -2- onto the vacuum connection far enough so that it audibly engages.

Insert the connector -1- into the clip on the brake system vacuum pump -- mount.

BRAKE BOOSTER PRESSURE SENSOR -G294

Note. The brake booster pressure sensor -- is installed inside the plenum chamber in front of the brake booster. The plenum chamber cover must be removed.

Removing

Remove plenum chamber cover.

Disconnect the harness connector -1-.

Scheme 36

Carefully pry down Brake Booster Pressure Sensor -G294- and remove.

Installing

Install in reverse order of removal.

VACUUM PUMP, TURBO FSI 4-CYLINDER

Note. Before removing the vacuum pump, the fuel high pressure pump must be removed, refer to [For engine(s) CAEB] High Pressure Pump . The plenum chamber bulkhead does not have to be removed.

Removing

The vacuum pump is installed in the engine compartment facing the rear -arrow-.

Scheme 37

Remove the engine covers carefully from the retaining pins, one after another.

Scheme 38

The vacuum pump is installed in the engine compartment on the right side facing the rear.

Remove the small vacuum hose from the fuel line.

Remove the fuel line bracket on the vacuum pump and fuel high pressure pump.

Disconnect the fuel high pressure pump connector -1-.

Scheme 39

Remove the fuel high pressure pump -2-, refer to [For engine(s) CAEB] High Pressure Pump .

Disconnect the vacuum hose at the hose clamp to the vacuum pump.

Remove all the screws on the vacuum pump sealing flange -arrows-.

Scheme 40

Note. Do not disconnect the vacuum hose from the vacuum line on the plenum chamber bulkhead -2-.

Remove the vacuum pump from the mount.

Installing

Note. Replace the seals. Make sure the seals are correctly installed.

Position the vacuum pump tappet so it engages in the groove on the camshaft when vacuum pump is installed.

Install and tighten all the bolts -arrows- on the vacuum pump sealing flange, refer to -Item 1- VACUUM PUMP OVERVIEW .

Push the new hose clamps over the vacuum hose.

Push the vacuum hose over the connection to the vacuum pump.

Compress the hose clamp on the vacuum pump connections with pliers.

Install the fuel high pressure pump, refer to [For engine(s) CAEB] High Pressure Pump .

Install the fuel line bracket on the vacuum pump and fuel high pressure pump.

Connect the small vacuum hose to the fuel line.

Connect the fuel high pressure pump connector -1-.

Install the engine cover.

BRAKE 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

Tighten hex collar nuts -1- through -4- to 14 Nm.

Tighten hex collar nuts -5- and -6- to 14 Nm.

Scheme 41

Brake Hose to Brake Caliper to Front Axle

Item -1- brake hose, ensure retaining tabs are seated correctly in bracket.

Item -2- retaining spring.

Tighten brake pipe line -3- to 14 Nm.

Scheme 42

Brake line -1-.

Item -2- retaining spring.

Item -3- brake hose, ensure retaining tabs are seated correctly in bracket.

Scheme 43

Brake Line Routing in Wheel Housing to Front Axle

Item -1- brake pipe line, 14 Nm tightening specification.

Item -2- intermediate piece.

Item -3- brake pipe line, 14 Nm tightening specification.

Scheme 44

Brake Line Connecting in Wheel Housing to Front Axle

Item -1- brake hose bracket.

Tighten brake line -2- to 14 Nm.

Scheme 45

Brake Line Routing to Rear Axle

Tighten the -1- brake hose in the brake caliper to 20 Nm.

Item -2- brake hose bracket, ensure retaining tabs are seated correctly in bracket.

Item -3- retaining spring.

Tighten brake line -4- to 14 Nm.

Scheme 46

SPECIAL TOOLS

Special tools and workshop equipment required

Scheme 47

Scheme 48

Scheme 49

Scheme 50

Scheme 51

Scheme 52

1. Trim Removal Wedge 3409
2. Piston Resetting Tool T10145
3. Adapter VAS 5234/1
4. Brake Charger/Bleeder Unit VAS 5234
5. Brake Pressure Gauge 0-250 bar V.A.G 1310A
6. Brake Servo Tester VAS 6721
7. Hand Vacuum Pump VAS 6213
8. Torque Wrench 5-50 Nm V.A.G 1331

See also:
• GENERAL INFORMATION
• Removal and Installation
• BRAKE PEDAL, WITH MANUAL TRANSMISSION
• BRAKE PEDAL, WITH AUTOMATIC TRANSMISSION
• BRAKE LAMP SENSOR
• BRAKE CALIPER WITH FRONT BRAKE CARRIER, FBC-60, REMOVING AND INSTALLING
• Removal and Installation
• BRAKE PEDAL AND BRAKE BOOSTER, DISCONNECTING AND CONNECTING
• BRAKE FLUID RESERVOIR
• BRAKE FLUID RESERVOIR COVER
• BRAKE BOOSTER
• MASTER BRAKE CYLINDER
• PROTECTIVE CAP AND GUIDE PINS, FBC BRAKES
• Brake System Vacuum Pump -V192
• Brake System Vacuum Pump -V192-, CHECKING
• CHECK VALVE, CHECKING
• Brake Booster Pressure Sensor -G294
• REAR BRAKE CALIPER PISTON
• REAR BRAKES GUIDE PINS AND PROTECTIVE CAPS
• Brake Servo Tester VAS 6721, CONNECTING
• VACUUM, CREATING USING Hand Vacuum Pump VAS 6213
• BRAKE SYSTEM, BLEEDING
• VACUUM PUMP OVERVIEW