Buick Regal Owners & Service Manuals
Buick Regal 2018-2024 Service Manual / Brakes / Hydraulic Brakes / Description and Operation / Brake Assist System Description and Operation

Buick Regal: Brake Assist System Description and Operation

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.

At rest, source vacuum is applied to both sides of the vacuum diaphragm for single boosters, or to both sides of each of the diaphragms for tandem boosters. Return springs maintain the booster in a rest position.

When brake system input force is applied, vacuum to the rear of the diaphragm(s) is cut off, and air at atmospheric pressure is admitted in its place. This provides a decrease in brake pedal effort required. When input force is removed, vacuum again replaces atmospheric pressure within the booster.

Vacuum Source

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

The primary source for vacuum is typically the vehicle's internal combustion engine. Some vehicles may use a vacuum pump to ensure and adequate supply of vacuum under various operating conditions, such as during cold start-up, heavy throttle, and high altitude.

Vacuum Monitoring System

Provides a feedback voltage signal relative to the amount of vacuum available for the vacuum power brake booster.

This typically consists of a vacuum sensor mounted either into the power vacuum brake booster, integrated with the vacuum check valve, or in-line within the vacuum hose. The sensor feedback is typically monitored by the powertrain control module(s).

Vacuum Source Control

If equipped with a system to monitor available levels of vacuum for the brake assist system, the powertrain control module(s) typically perform the primary monitoring function.

The powertrain controller will typically monitor the feedback signal of a vacuum sensor, as it relates to available vacuum at the vacuum power brake booster. The powertrain controller uses the information to make sure available vacuum remains above predetermined levels. If additional vacuum is required, the powertrain controller may reactivate engine cylinders, if equipped, or command a vacuum pump ON, if equipped, and/or may alter the operation of various other engine controls and devices, as necessary.

Vacuum Source Delivery System

Enables delivery and retention of source vacuum for vacuum brake booster.

This typically consists of a vacuum check valve and a vacuum hose or pipe. If a vacuum pump is used, additional check valves may be used.

System Operation

Brake system input force from the driver 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 operation of the vacuum brake booster.

When brake system force is applied, vacuum to the rear of the diaphragm(s) is cut off, and air at atmospheric pressure is admitted in its place. The vacuum acts to pull the diaphragm(s) forward, while the atmospheric pressure acts to push from behind. As a result, the amount of effort required by the driver is reduced. When input force is removed, vacuum again replaces atmospheric pressure within the vacuum power brake booster to help return the booster to rest.

If the vehicle is equipped with a vacuum monitoring system, the powertrain control module(s) typically will alter powertrain functions and/or command the vacuum pump ON, if equipped, to provide for the vacuum needs of the brake assist system, as operating conditions warrant.

    READ NEXT:

     Brake Booster Vacuum Assist Description and Operation

    System Component Description B19B - B19B Brake Booster Vacuum Sensor K17 - K17 Electronic Brake Control Module M9 - M9 Brake Booster Pump Motor The brake booster vacuum assist system consists of the

     Hydraulic Brake System Description and Operation

    System Component Description The hydraulic brake system consists of the following: Hydraulic Brake Master Cylinder Fluid Reservoir Contains supply of brake fluid for the hydraulic brake system. Hydrau

     Park Brake

    SPECIFICATIONS FASTENER SPECIFICATIONS Single Use Non-Threaded Fasteners/Components NOTE: All fasteners/components listed in this table MUST BE DISCARDED and replaced with NEW after removal. Applicati

    SEE MORE:

     Intermediate Steering Shaft Boot Replacement (Outer)

    Special Tools CH-804 Drive Axle Boot Clamp Pliers Equivalent regional tools:Special Tools Removal Procedure 1. Intermediate Steering Shaft Inner Boot(1) - Remove. 2. Remove the front tire and wheel assembly. 3. Cut the intermediate steering shaft outer boot clamp (1). DISCARD the clamp. 4. Sl

     Rear Window Wiper/ Washer

    If equipped, the ignition must be on or in ACC/ACCESSORY to operate the rear window wiper/washer. Turn the end of the windshield wiper lever to operate the rear window wiper/washer. OFF : Turns the system off. INT : Intermittent wipes. ON : Slow wipes. : Push the windshield wiper lever forward

    © 2019-2024 Copyright www.buregal6.com