4-Cylinder Diesel Engine
Brake Booster
Special tools, testers and auxiliary items required
• Release tool (T10159 A)
• Sealing tool (T10249)
• Torque wrench (V.A.G 1331)
• Brake filler/bleeder unit (VAS 5234)
• Plug (1H0 698 311 A)
• Hose clamp pliers (VAS 6340)
• Engine bung set (VAS 6122)
Removing
The engine cover bracket on the cylinder head cover can break if it is removed incorrectly. Always remove the engine cover according to the following procedure.
- Pull the engine cover - arrows - upward out of the fasteners in the given sequence.
- Reach under the engine cover as far as possible.
- Remove the intake hose.
- Release the spring clips - arrows - and remove the cover for the air guide.
- Release the left and right spring clips - arrow A - and unclip the lower air guide - 2 -
- Disengage the lower air guide - 3 - by moving it to the side.
- Disengage the air guide pipe - 1 - from the lower air guide - arrow B -
- Disconnect the connector - 1 - from the mass airflow sensor (G70) and remove the hose - 2 -.
- Open the clamp - 4 - and remove the air guide hose.
- Remove the screw - 3 - and remove the air filter housing.
- Seal off all openings with (VAS 6122).
• Disconnect battery ground strap for all further work. See if a coded radio is installed. Get the anti-theft code beforehand, if necessary.
- Remove battery and the battery carrier.
- Remove bolts - Arrows -.
• Danger of causing damage to electronic components when disconnecting the battery.
• Complete the steps for disconnecting the battery.
- Press the release buttons and remove the crankcase ventilation hose - 1 - from the cylinder head cover.
- Disconnect the connector from the crankcase ventilation hose - 1 -.
- Free up the vacuum hoses - arrow -.
- Remove bolt - 2 -.
- Turn the air guide pipe to the rear and remove it.
- Remove the bolt - arrow -.
- Remove the intake tube - 1 - for the preglow on the bracket.
- Remove the bolts - arrows - and the pulsation damper.
- Loosen the clamp and remove the charge air pressure sensor - 2 - from the charge air cooler - 1 -.
- Remove bolt - arrow -.
- Free up the electric wires and hoses on the air guide pipe - 1 - using the (80 - 200).
- Loosen the clamp - 2 - and remove the air guide pipe - 1 -.
- Place sufficient lint-free cloths in the area of the engine and transmission.
- Extract as much brake fluid as possible from the brake fluid reservoir using (VAS 5234).
Vehicles with DSG Transmission
- Remove the selector lever cable from the ball head and out of the cable bracket
- Remove the selector lever from the selector shaft on the transmission.
- Remove the bracket from the selector lever cable on the transmission.
Continuation for All Vehicles
- Remove the vacuum line - 1 - from the brake booster.
- Remove the star-shaped washers - arrows -.
- Disconnect the connector.
- Unclip the connector and wiring harness from the bulkhead.
- Fold the bulkhead damper - 1 - forward in - direction of arrow - and remove it.
• It is not necessary to remove the insulation.
With Manual Transmission
- Remove the supply hose - 2 - for the clutch master cylinder - 3 - from the brake fluid reservoir - 4 -.
- Seal the supply hose - 2 - for the clutch master cylinder - 3 - using (T10249) - 1 - or (VAS 6122).
- Seal off the supply hose - 2 -.
- Remove the selector mechanism from the transmission.
• It is necessary to separate the cable retainer from the selector cable prior to removing to prevent damaging the selector cable.
Continuation for All Vehicles
- Disconnect the connector - 1 - from the brake fluid level warning switch (F34).
- Remove the brake line tube fitting - 2 -.
- Seal off the brake line with the plug (1H0 698 311 A).
- Pry the brake fluid reservoir - 1 - off the retainers - arrows - on the master brake cylinder - 2 -.
- Carefully remove the brake fluid reservoir - 1 - from the plug.
- Release and disconnect the connector - 1 - from the brake lamp switch (F) - 2 -.
- Unclip the cable bracket from the master brake cylinder.
- Remove the brake line tube fitting - 2 - from the master brake cylinder - 1 -.
- Seal off the brake line with the plug (1H0 698 311 A).
- Unscrew the threaded connection - arrows - on the brake master cylinder - 1 -.
- Carefully take brake master cylinder out of brake booster.
- Disconnect brake pedal from brake booster. Refer to => [ Brake Pedal and Brake Booster, Separating and Connecting ] Brake Pedal and Brake Booster, Separating and Connecting.
- Remove the threaded connection - 1 - from the brake booster on the pedal bracket.
• It is not necessary to loosen the threaded connection - 2 -.
- Carefully remove the brake booster from the vehicle.
Installing
Install in reverse order of removal. Note the following:
- Carefully install the brake booster and tighten the nuts hand-tight.
- When installing together the brake master cylinder and brake booster, make sure that the push rod is correctly located in the brake master cylinder.
- Make sure the seal fits correctly when attaching the master brake cylinder to the brake booster.
- Clip the brake pedal to the brake booster. Refer to => [ Hold the push rod ball head in front of the mount and push the brake pedal toward the brake booster until the ball head engages audibly. ] Brake Pedal and Brake Booster, Separating and Connecting.
Follow the Tightening Sequence:
- Tighten bolts - 1 - through - 4 - in the same sequence as illustrated.
Coat the plugs with brake fluid before pushing the brake fluid reservoir into the master brake cylinder.
- Bleed hydraulic system. Refer to => [ Hydraulic System, Bleeding ] Service and Repair.
With Manual Transmission
- Bleed the clutch.
Continuation for All Vehicles
- Insert the tab on the vacuum line - 1 - into the opening - arrow - in the brake booster - 2 -.
- Install and connect the battery.
- Make sure the rubber buffers fit correctly in the mounts when installing the engine cover.
Before installing the engine cover, make sure the 4 mounting elements (ball sockets) are correctly positioned; adjust them if necessary. Otherwise the engine cover will get damaged.
Tightening Specification
