Hydraulic Brake System Description and Operation. Chevrolet Joy 2008

For 1990-2009 cars

Caution: Refer to Brake Fluid Irritant Caution in the Preface section.

The master cylinder is designed for use in a direct-split system. Front right brake and rear left brake are served by the primary piston. Front left brake and rear right brake are served by the secondary piston.

The master cylinder incorporates the functions of the standard dual master cylinder, plus a low fluid level indicator and the proportioning valve in the non-antilock braking system.

The proportioning valves limit the outlet pressure to the rear brakes after a predetermined master cylinder has been reached.

• | Replace all the components included in the repair kits used to service this master cylinder.

• | Lubricate rubber parts with clean brake fluid to ease assembly.

• | Do not use lubricated shop air on brake parts, as this may damage rubber components.

• | If any hydraulic component is removed or disconnected, it may be necessary to bleed all or part of the brake system.

• | The torque values specified are for dry, unlubricated fasteners.

• | Perform all service operations on a clean bench, free from all traces of mineral oil.

### Proportioning Valve

The proportioning valve limits the outlet pressure to the rear brakes on the non-ABS after a predetermined master cylinder pressure has been reached. This is used when less rear apply force is needed to obtain optimum braking and is usually found on disc/drum brake configurations. On ABS-equipped vehicles, refer to ABS Description and Operation .

### Fluid Level Sensor

Fluid level sensor is attached at the brake fluid reservoir. This sensor will activate the BRAKE light if a low fluid level condition is detected. Once the fluid level is corrected, the BRAKE light will go out.