Brake Vacuum Assist System Operation
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2002 GMC Yukon XL, 2002 GMC Yukon, 2002 Chevrolet Tahoe, 2002 Chevrolet Suburban, and 2002 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
Brake system input force is multiplied by the brake pedal and transferred by the pedal pushrod to the hydraulic brake master cylinder. Effort required to apply the brake system is reduced by the vacuum brake booster.