Exploded view - tandem brake servo / brake master cylinder (LHD vehicles) — AUDI
Exploded view - tandem brake servo / brake master cylinder (LHD vehicles) on Audi: factory workshop procedure. Full factory text, tools and checks.
Workshop procedure for AUDI — the factory write-up, straight from real workshop data.
📋 Procedure
ℹ️ Torque figures below come verbatim from workshop data — always cross-check against your vehicle's factory manual before final tightening.
Audi
Audi A4
2001
Audi A4 Cabriolet
2003
Running gear
Brake system
Edition
04.2013
Exploded view - tandem brake servo / brake master cylinder (LHD vehicles)
Note
Brake master cylinders can no longer be dismantled, i.e. servicing is not envisaged.
Use only new brake fluid. Observe information on brake fluid reservoir!
Assignment of brake line connections
1
a
Vacuum hose
On petrol engines the vacuum required is taken from the intake manifold and/or a mechanical vacuum pump.
Insert into brake servo unit
1
b
Vacuum hose
On petrol engines the vacuum required is taken from the intake manifold and/or a mechanical vacuum pump.
An additional electrical vacuum pump is installed on vehicles where vacuum is taken from intake manifold only
Insert into brake servo unit
2
Trunnion bolt, 8 Nm
Screw in as far as stop
Unscrew to remove brake fluid reservoir
3
Brake fluid reservoir with float warning indicator
Checking function
With the ignition switched on, remove the filler cap and press with your hand on the strainer that is visible in the reservoir. Warning lamp in instrument cluster should light up and acoustic alarm should sound.
Removing and installing
Chapter
Refer to label on reservoir before topping up brake fluid
4
Filler cap
5
Sealing plug
Moisten with brake fluid and insert into brake master cylinder
Press brake fluid reservoir into sealing plugs
6
Brake servo
Removing and installing
Chapter
Adjusting ball head
Fig.
Checking function
With the engine switched off, firmly depress the brake pedal several times (this reduces the vacuum present in the servo unit).
Then hold brake pedal in applied position employing moderate force and start engine. If the servo unit is working properly, the pedal will give slightly under foot (servo assistance becomes activated).
Renew complete unit if defective
7
Pedal bracket
8
Supply hose
Keep both ends closed off until it is installed.
Push on the hose as far as it will go.
9
Bulkhead
10
Bolt, 25 Nm
11
Flange nut, 50 Nm
Always renew
12
Brake master cylinder
Cannot be repaired. If faulty, renew complete.
Has to be removed and installed together with the brake servo unit.
Removing and installing
Chapter
13
Brake line, 15 Nm
Brake master cylinder/primary piston circuit to hydraulic unit
Brake master cylinder/secondary piston circuit to hydraulic unit
14
Seal
Insert into groove on brake master cylinder
Renew after removing brake master cylinder
TorqFix answers live for your specific car — tell it the engine code and it serves the matching sequence, torque figures and wiring for that exact variant.
Ask about my car →Other AUDI procedures
- Removing and installing toothed belt – Audi · 56 torque figures
- Removing engine – Audi A8 D3 · 41 torque figures
- Removing camshaft timing chain from camshafts – Audi A6/A7 C7 · 38 torque figures
- Installing engine – Audi A8 D4 · 36 torque figures
- Removing and installing camshaft timing chain · 29 torque figures
- Removing and installing oil pump - from engine number BSM 006 226 onwards
- Removing and installing auxiliary radiator (left-side) – Audi
- Removing and installing exhaust pipes (left-side) – Audi BSM
- Intake manifold (bottom section) with fuel rail - exploded view · 1 torque figures
- 6-speed manual gearbox 0A2, front-wheel drive — Removing and installing selector shaft locking bushes (with gearbox installed in vehicle)
Who makes these pages, and how
TorqFix was built by a mechanic — after a 2,700 km drive with five roadside repairs that no diagnostic tool could explain.
The figures on this page come from manufacturer workshop documentation and are shown as they are. The page is assembled automatically from that data — it is not written by an AI. The AI works in the chat, where it answers for your specific car. It writes nothing here.
Variants of the same model differ. Cross-check torque against the factory manual for your engine before final tightening.
Seen a figure that does not match your manual? Write to us — we correct it and note when. support@torqfix.com
The story behind TorqFix →Workshop data on this page last updated 20 Sep 2026.