Withdrawal
Remove the brake fluid from the reservoir with a syringe.
On the model «323i» remove the fuel injection mixture regulator.
Remove the locking clip and disconnect the pusher of the vacuum booster from the brake pedal.
Disconnect the pipelines from the main cylinder and close the openings at the pipelines and at the main cylinder. Disconnect the hose from the booster.
Remove the nuts securing the vacuum booster to the bulkhead shield bracket and to the bracket on the fender mudguard.
Remove the vacuum booster assembly with the master cylinder by pushing it forward.
Remove the protective cover, gasket, buffer washer and replace the vacuum booster air filter.
Installation
Installation of the vacuum booster is carried out in the reverse order of removal. When attaching the booster pushrod to the brake pedal, ensure protrusion «A» stoplight switch button, equal to 5-6 mm.
After installing the vacuum booster, bleed the brake system to remove air from it.
Check valve replacement
Removing the check valve is not difficult. Install the new valve with the arrow or black side toward the intake manifold. Replace the clamps each time the check valve is removed.