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

WARNING: This page is about a different car, the 2024 Audi S6 and 2024 Audi A6 Quattro. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION:

Deformation increases the risk of damage.

- Do not hold the brake booster on the actuator rod.

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

Make sure that the actuator pin for the brake lamp is pushed into the brake master cylinder. If this pin is missing, the brake lamp will not function.
Check the vacuum hoses for damage before the assembly and replace if necessary.
Do not let any brake fluid run into the brake booster.

CAUTION:

Risk of overheating the brakes due to the incorrect positioning of the actuator rod.

- Before installing the brake booster, measure the length of the actuator rod.

-- Adjust the actuator rod length with the ball head to the correct dimension. Refer to Figure.

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

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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.

If deformed, service the bulkhead or replace the brake booster.

-- 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 => List Item:Bolt.

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-- Push the vacuum hose into the brake booster.

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-- Install the Vacuum Sensor -G608- -2-. Refer to Vacuum Sensor -G608-, REMOVING AND INSTALLING .

-- Slide the vacuum hose firmly onto the Vacuum Sensor -G608-.

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 -item 1- OVERVIEW - BRAKE BOOSTER/BRAKE MASTER CYLINDER, VACUUM BRAKE BOOSTER => List Item:Brake Line and -item 22- OVERVIEW - BRAKE BOOSTER/BRAKE MASTER CYLINDER, VACUUM BRAKE BOOSTER => List Item:Brake Line.

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

-- Install the windshield wiper motor. Refer to WINDSHIELD WIPER MOTOR V, 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.

Fig 1: Brake Fluid Reservoir

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-- Connect the brake pedal to the brake booster. Refer to BRAKE PEDAL, DISCONNECTING FROM 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.