Audi Q3: Overview - Brake Booster/Master Brake Cylinder
Note
Brake master cylinder and brake boosters can be replaced
independently of one another.

1 - Heat Shield
2 - Nut
- 25 Nm
- Always replace if removed
- Self-locking
3 - Sealing Plug
- Coat with brake fluid and press into brake fluid reservoir
4 - Bolt
5 - Brake Fluid Reservoir
- Removing and installing, refer to
→ Chapter "Brake Fluid Reservoir, Removing and Installing".
6 - Seal
7 - Cap
8 - Grommet
9 - Brake Booster
- Functional check:
- With engine switched off, depress brake pedal firmly several times
(to exhaust the vacuum in the unit).
- 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).
- Disconnect from brake pedal, refer to
→ Chapter "Brake Pedal, Removing from Brake Booster".
- Removing and installing, refer to
→ Chapter "Brake Booster, Removing and Installing".
10 - Seal
11 - Nut
- Tightening specification and sequence, refer to item -2-.
12 - Seal
13 - Bolt
14 - Brake Lamp Switch -F-/Brake Pedal Switch -F63-
- Removing and installing, refer to
→ Chapter "Brake Lamp Switch, Removing and Installing".
15 - Brake Master Cylinder
- Cannot be serviced
- If malfunctioning: replace as complete unit.
- Removing and installing, refer to
→ Chapter "Brake Master Cylinder, Removing and Installing".
16 - Rubber Buffer
READ NEXT:
Note
The Brake Lamp Switch -F-/Brake Pedal Switch -F63- is
installed in the brake master cylinder.
Removing
Audi RS Q3:
- Remove the air filter housing, refer to
→ Engine
Special tools and workshop equipment
required
Brake Charger/Bleeder Unit -VAS5234-
Sealing plugs from Repair Kit -1H0 698 311 A-
Removing
- Remove the brake fluid reservoir,
1 - Brake System Vacuum Pump -V192-
Allocation, refer to the Parts Catalog.
Installed location: in the engine compartment over the engine
transmission separating point.
Do not di
SEE MORE:
Driver/Front Passenger Seat Heating Element -Z6-/-Z8-, Removing and
Installing, Fabric Cover Versions
Procedure
- Separate the seat cover from the seat cushion. Refer to
→ Chapter "Seat Pan Cover and Cushion, Separating".
Standard seat and folding seat:
- Disconnect the wire
Brake Fluid General Information
Brake fluid is hygroscopic, for example it has the ability
to absorb water and moisture from the air.
If water has been absorbed, the boiling point will drop, for
example, during high braking temperatures the brake fluid may
develop steam bubbles and cause the