Brake Booster
WARNING: This page does not describe the selected car, but rather 11 other vehicles, including the 2005 BMW 760i, 2005 BMW 760Li, 2005 BMW 745i, 2005 BMW 745Li, and 2004 BMW 760i. However, it is still accessible from the selected car via links, so may be relevant.
- Release clamp (1) on microfilter air duct. See Fig 1. Press lock (3) and fold up complete microfilter air duct (4) in direction of arrow. Remove complete microfilter air duct (4) from fresh air duct (2).
- Detach hose from connection piece. Install vacuum tester (34 3 100) between connection piece and vacuum hose of non-return valve. See Fig 2.
- Start engine. Check buildup of partial vacuum.
- Switch off engine. Press brake pedal to set a vacuum pressure of not more than 12 psi (0.8 bar) and wait for the value to stabilize.
- Release the brake pedal. Vacuum pressure should not drop more than 9 psi (0.6 bar) over a period of one minute.
- If specifications are not reached, perform the following:
- Check line connections for vacuum seal.
- Replace non-return valve.
- Check seal between brake booster and brake master cylinder (sealing ring) for perfect condition and correct seating.
- Perform test again. If specifications are not reached, replace brake booster. See BRAKE BOOSTER under REMOVAL & INSTALLATION.