Audi Workshop Service and Repair Manuals

Removing and installing brake master cylinder

Special tools and workshop equipment required

t	Hose clamps up to 25 mm diameter -3094-

t	Torque wrench -V.A.G 1331-

t	Brake filling and bleeding equipment -V.A.G 1869-

t	Upgrade kit and extraction unit -V.A.G 1869/4-

t	Brake filling and bleeding equipment -VAS 5234-

t	Sealing plug repair kit, Part No. -1H0 698 311 A-

Removing –  Remove engine cover.

–  Remove bolt -3-. –  Place air cleaner housing to side.

–  Remove battery. → Rep. gr.27 –  Remove battery tray -arrows-. –  Detach battery tray from air duct at front. –  As protection against escaping brake fluid, place a sufficient number of lint-free cloths in area beneath brake master cylinder. –  Use the brake filling and bleeding equipment -VAS 5234- or the upgrade kit and extraction unit -V.A.G 1869/4- to extract as much brake fluid as possible from brake fluid reservoir.

–  Clamp off supply hose of clutch master cylinder with hose clamps up to 25 mm diameter -3094-. –  Pull off supply hose for clutch master cylinder. –  Detach connector for brake fluid level warning contact.

–  Disconnect brake lines -3- from brake master cylinder and seal brake lines with plugs from repair kit. –  Unscrew securing nuts -1- for brake master cylinder. –  If fitted, remove heat shield with retaining plate. –  Pull brake master cylinder off brake servo. –  Unclip brake fluid reservoir at position -2- and pull off upwards. Installing Installation is performed in reverse sequence; note the following: –  Renew seal between brake master cylinder and brake servo. –  When inserting brake master cylinder, make sure that push rod is correctly positioned in brake servo. –  Depress brake pedal slightly to facilitate insertion of brake master cylinder in pushrod. –  Bleed brake system: ABS/ESP Mark 60 → Chapter. –  Bleed clutch hydraulics: → Rep. gr.30 –  On vehicles with ABS/ESP, start basic setting for brake pressure sender 1 -G201-. To do so, use the vehicle diagnosis, testing and information system -VAS 5051 x - or -VAS 5052-. –  Carry out ESP road test and system test. To do so, use the vehicle diagnosis, testing and information system -VAS 5051 x - or -VAS 5052-. –  See: Running gear –  Brake system (Repair group 01; 45) –  01 - Self-diagnosis compatible systems –  03 - Brake electronics ABS/ESP Mark 60 –  J104 - Control unit for ABS/TCS/ESP, Functions Tightening torques

Component		Nm
Brake master cylinder to brake servo		25
Brake line to brake master cylinder		14
Battery tray to body		10

Renew nuts 1)  Renew nuts