Brake Booster, Removing And Installing, Vacuum Brake Booster: Installing

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Install in the reverse order of removal while noting the following:

Do not move/transport the brake booster by the actuator rod.
Make sure that the actuator pin -item 19- OVERVIEW - BRAKE BOOSTER/BRAKE MASTER CYLINDER, VACUUM BRAKE BOOSTER for the brake lamp is pushed into the brake master cylinder. If this pin is missing, the brake lamp will not function.
Replace the seal in between the brake booster and the bulkhead after dismounting.
Check the vacuum hoses for damage before the assembly and replace if necessary.
Do not let any brake fluid run into the brake booster.

-- Check that the boot -2- has not slipped out of the surrounding groove -arrow- on the brake booster -1- as shown.

Courtesy of AUDI

The boot -2- must rest securely in the groove all the way around -arrow-.

-- Before installing the brake booster thoroughly clean the contact surface on the brake booster and the bulkhead.

CAUTION:

Installing the brake booster incorrectly increases the risk of malfunctions.

- Check the contact surface on the bulkhead. It must be flat and not deformed.

- Check the contact surface on the brake booster. It must be flat and not deformed.

-- Install the brake booster with the master brake cylinder.

After inserting the in the vehicle the brake booster must be flat and completely on the new seal.

-- Install the bolts -arrows- and tighten to the required tightening specification -item 3- OVERVIEW - BRAKE BOOSTER/BRAKE MASTER CYLINDER, VACUUM BRAKE BOOSTER (example illustration).

Courtesy of AUDI

-- Push the vacuum hose into the brake booster.

Courtesy of AUDI

-- Slide the vacuum hose -2- tightly onto the Vacuum Sensor -G608- (example illustration).

Make sure the vacuum hose is connected at all of the separating points.

-- Connect the connector -1- for the Vacuum Sensor -G608- and connector -4- for the Brake Lamp Switch -F-.

CAUTION:

Risk of destroying the brake lines by bending.

- Never change the shape of the brake lines.

-- Insert the brake lines into the brake master cylinder by hand.

-- Tighten the union bolts -3- for the brake lines to the required tightening specification.

-- Install the brake fluid reservoir. Refer to BRAKE FLUID RESERVOIR, REMOVING AND INSTALLING .

-- Install the plenum chamber bulkhead. Refer to PLENUM CHAMBER BULKHEAD, REMOVING AND INSTALLING .

-- Fill the brake fluid reservoir up to the "MIN" mark (example illustration).

Fig 1: Brake Fluid Reservoir

Courtesy of AUDI

-- Connect the brake pedal to the brake booster. Refer to BRAKE PEDAL, ATTACHING TO BRAKE BOOSTER .

-- Remove all cloths from the vehicle that were previously placed down.

-- Bleed the brake system. Refer to HYDRAULIC SYSTEM, BLEEDING .

Make sure the brake lamp functions correctly.

CAUTION:

Faulty brakes increase the risk of an accident.

- Make sure the brakes are working correctly before driving the vehicle for the first time.