Brake Assist System Description and Operation LH Drive, Vacuum Assist

System Component Description

The brake assist system consists of the following:

Brake Pedal: Receives, multiplies and transfers brake system input force from driver.

Brake Pedal Pushrod: Transfers multiplied input force received from brake pedal to brake booster.

Vacuum Brake Booster: Uses source vacuum to decrease effort required by driver when applying brake system input force. When brake system input force is applied, air at atmospheric pressure is admitted to the rear of both vacuum diaphragms, providing a decrease in brake pedal effort required. When input force is removed, vacuum replaces atmospheric pressure within the booster.

Vacuum Source: Supplies force used by vacuum brake booster to decrease brake pedal effort.

Vacuum Source Delivery System: Enables delivery and retention of source vacuum for vacuum brake booster.

System Operation

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.

Brake Assist System Description and Operation RH Drive, Hydraulic Assist

System Component Description

The brake assist system consists of the following:

Brake Pedal: Receives, multiplies and transfers brake system input force from driver.

Brake Pedal Pushrod: Transfers multiplied input force received from brake pedal to brake booster.

Hydraulic Brake Booster: Uses closed-circuit brake fluid pressurized by hydraulic brake booster pump to decrease effort required by driver when applying brake system input force. When brake system input force is applied, pressurized closed-circuit brake fluid is admitted to the rear of an apply piston, providing a decrease in brake pedal effort required. When input force is removed, pressurized closed-circuit brake fluid is blocked off from the piston.

Hydraulic Brake Booster Pump: Supplies pressurized brake fluid used in a closed-circuit by hydraulic brake booster to decrease brake pedal effort.

System Operation

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 hydraulic brake booster.