2003 Buick Regal Brake Service (ONLINE REPAIR MANUALS)

Service Brake

• Raise and support vehicle.
• Mark relationship of wheel to axle, then remove wheel and tire assembly.
• Remove brake drum. If drum is difficult to remove, proceed as follows:
• Ensure parking brake is released.
• Back off parking brake cable adjustment.
• Remove access hole plug from backing plate, insert screwdriver through hole and push parking brake lever off its stop.
• Insert punch through hole in splash shield, Fig. , tap on punch to loosen drum, then remove drum.
• Measure inside diameter of drum using tool Nos. J-21177-A or J-22364-01, or their equivalents.
• Adjust by turning star whe...

Brake System Bleed

In most circumstances a manual brake bleed is all that is required. Automated ABS bleeding is required under the following conditions: when manual bleeding does not achieve desired pedal height or feel; brake pressure modulator valve (BPMV) replacement; extreme loss of brake fluid; air ingestion is suspected.

Manual Bleed

Use suitable container to catch fluid.

• Clean reservoir cover and surrounding area.
• Remove cover, fill fluid reservoir and install cover.
• Attach one end of a clear plastic hose to rear hydraulic modulator bleeder valve, then submerge other end of hos...

ABS Service

Before performing any repairs on the ABS system, note the following precautions:

• Before using electric welding equipment, disconnect EBCM.
• Carefully note routing, position and mounting ABS and TCS wiring, connectors, clips and brackets. ABS and TCS are extremely sensitive to electromagnetic interference.
• Do not use a fast charger when battery is connected. Never disconnect battery from system with engine running.
• Ignition switch must be in Off position when disconnecting EBCM.
• Many ABS system components ...

Replacement

• Remove ^2/3 of brake fluid from master cylinder reservoir.
• Raise and support vehicle.
• Mark relationship of wheel to axle flange, then remove wheel and tire assembly.
• Using a suitable C-clamp, compress caliper piston enough for clearance.
• Remove brake hose from caliper plug openings in caliper and brake hose to prevent fluid loss and contamination.
• Remove caliper bolts, then the caliper housing from rotor and caliper bracket.
• Reverse procedure to install.

Disassemble

• Pad interior of caliper assembly with a clean shop towel, then remove piston assembly using low pressure compres...

Master Cylinder Overhaul

Except Aurora, Bonneville, Corvette, CTS, Eighty-Eight, LeSabre, Park Avenue, Riviera & Vibe

Disassemble

Refer to Figs. and , when performing the following procedures.

• Disconnect and plug hydraulic lines.
• Remove mounting nuts and master cylinder.
• Remove reservoir cover and diaphragm. Discard old brake fluid in reservoir.
• Inspect cover and diaphragm.
• Remove fluid level switch, if equipped.
• On models equipped with compact master cylinder, remove proportioner valve, Fig. .
• On all models, depress primary piston and remove lock ring.
• Plug primary fluid outlet (outlet...

Brake Roughness

The most common cause of brake chatter on disc brakes is a variation in disc thickness. If roughness or vibration is encountered during highway operation or if pedal pulsation is experienced at low speeds, the disc may have excessive thickness variation. To inspect for this condition, measure the disc at 12 points with a micrometer at a radius approximately one inch from edge of disc. If thickness measurements vary by more than ...