Removing and installing brake master cylinder, LHD vehicles

Special tools and workshop equipment required

Brake filling and bleeding equipment -VAS 5234-

Torque wrench -V.A.G 1331-

Sealing tool -T10249-

Removing

• If vehicle has a coded radio, note radio code or, if necessary, request it.
• Disconnect battery → Electrical system; Rep. gr.27
• Remove battery → Electrical system; Rep. gr.27.

Vehicles with diesel engine:

• Remove engine cover panel.
• Loosen hose clip -1- and remove air intake hose and air filter housing → Rep. gr.23.

On »R« vehicles:

• Loosen hose clips -2- and -3-.
• Remove air intake hose -1- and air filter housing → Rep. gr.24.

Continuation for all models:

• Remove battery tray → Electrical system; Rep. gr.27.
• Place sufficient lint-free cloths in area of engine and gearbox.

• Draw off as much brake fluid as possible from brake fluid reservoir using brake filling and bleeding equipment -VAS 5234-.

Vehicles with manual gearbox:

• Pull off supply hose -1- for clutch master cylinder, seal it using sealing tool -T10249- and tie it up, or clamp off supply hose -1- for clutch master cylinder using commercially available tool, e.g. Hazet 4590, and pull it off.

Continuation for all models:

• Disconnect connector from brake fluid level warning contact -F34--3-, from vacuum sender -G608--2- (if fitted) and from brake light switch -F--1-.

• Unscrew Torx bolt -1- and pull brake fluid reservoir -2- out of sealing plugs.

• Unscrew brake lines -1- from brake master cylinder, and seal brake lines with plugs from repair kit with part no. 1H0 698 311 A.
• Unscrew nuts -2- from brake master cylinder.
• Remove heat shield (if installed).
• Carefully take brake master cylinder out of brake servo.
• Unscrew brake light switch -F- from brake master cylinder.

Installing

Install in reverse order of removal, observing the following:

• When assembling brake master cylinder with brake servo, make sure plunger rod is properly positioned in brake master cylinder.

Seals must be located in supply hose for clutch master cylinder.

• Bleed brake system → Chapter.

Specified torques

→ Chapter „Assembly overview - brake servo/brake master cylinder, LHD vehicles“