2005 Pontiac Bonneville Brake Service (ONLINE REPAIR MANUALS)

AC-Delco Tandem Diaphragm Type

This unit utilizes a vacuum power chamber, consisting of a front and rear shell, housing divider, front and rear diaphragm, plate assemblies, hydraulic pushrod and a diaphragm return spring, Fig. .

In normal operating mode, with service brakes in released position, the booster operates with vacuum on both sides of its diaphragms. When brakes are applied, air at atmospheric pressure is admitted to one side of each diaphragm to provide power assist. When the service brake is released, atmospheric air is shut off f...

Manual

Pressure bleeding is recommended for all hydraulic systems. However, if a pressure bleeder is unavailable, use the following procedure. Brake fluid damages painted surfaces. Immediately clean any spilled fluid.

• Remove vacuum reserve by pumping brakes several times with engine off.
• Fill master cylinder reservoir with clean brake fluid. Do not let reservoir fall below half full during bleeding procedure.
• If required, bleed master cylinder as follows:
• Loosen master cylinder forward brake line connection until fluid flows from reservoir, then tighten brake line.
• Have assistant t...

Brake fluid is corrosive to painted surfaces. Care must be taken not to allow brake fluid to come in contact with painted surfaces on vehicle.

When bleeding the brake system, always bleed righthand rear wheel circuit first, followed by the lefthand front, lefthand rear and, finally, righthand front.

Manual

Pressure bleeding is recommended for all hydraulic systems. However, if a pressure bleeder is unavailable, use the following procedure. Brake fluid damages painted surfaces. Immediately clean any spilled fluid.

• Remove vacuum reserve by pumping brakes several times with engine o...

Master Cylinder

Except ION & L-Series

• On Vibe models, remove air filer hose clamp and hose from throttle body.
• On all models, disconnect fluid level sensor retainer and electrical connector.
• Drain master cylinder reservoir brake fluid into suitable container.
• Plug hose.
• Disconnect master cylinder brake pipes. Plug open pipes.
• Remove mounting nuts and master cylinder.
• Remove reservoir, as required.
• Reverse procedure to install. Bleed hydraulic system as outlined in .

ION

• Remove underhood electrical center cover.
• Remove Connector Position Assurance (CPA) connector from brake fluid level...

Two basic types of power assist mechanisms are used: vacuum assist diaphragm assemblies, which use engine vacuum or, in some cases vacuum pressure developed by an external vacuum pump. The second type is a hydraulic pressure assist mechanism, which use pressure developed by an external pump (usually the power steering pump). Both systems act to increase the force exerted on the master cylinder piston by the operator. This in turn increases the hydraulic pressure delivered to the wheel cylinders while decreasing driver effort required to obtain acceptable stopping performance.

Vac...

Brake Pedal

Toyota/GM Single Diaphragm Type

• With engine running and brake pedal in rest position, measure distance between face of pedal and floor mat.
• Distance should be 5.850-6.244 inches.
• If distance is not as specified, adjust pedal height as follows:
• Remove lefthand lower instrument panel trim section and air duct.
• Loosen stop lamp switch sufficiently to access pedal adjustment.
• Loosen locknut and rotate pedal pushrod as required to obtain specified pedal height. Tighten locknut.
• Adjust brake lamp switch position so plunger lightly contacts pedal stopper and brake lamps are off when pe...