GM Service Manual Online
For 1990-2009 cars only

Symptom

Causes

Excessive Brake Pedal Travel

    â€¢ Leaking brake line or connection. Refer to Brake Fluid Leak .
    â€¢ Leaking piston. Refer to Front Brake Caliper Overhaul or Rear Brake Caliper Overhaul in Disc Brakes.
    â€¢ Leaking master cylinder (internal). Refer to Master Cylinder Overhaul .
    â€¢ Air in the brake system. Refer to Hydraulic Brake System Bleeding .
    â€¢ Contaminated or improper brake fluid. Refer to Hydraulic Brake System Flushing .
    â€¢ Worn out brake lining. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Uneven brake lining wear. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Brake assembly attachments loose. Refer to Brake Pad Inspection in Disc Brakes.
    â€¢ Excessive vehicle loading.

Brake Pedal Travel Gradually Increases

    â€¢ Leaking brake line or connection. Refer to Brake Fluid Leak .
    â€¢ Leaking piston. Refer to Front Brake Caliper Overhaul or Rear Brake Caliper Overhaul in Disc Brakes.
    â€¢ Leaking master cylinder (internal). Refer to Master Cylinder Overhaul .
    â€¢ Contaminated or improper brake fluid. Refer to Hydraulic Brake System Flushing .
    â€¢ Restricted passage in the vacuum booster. Refer to Vacuum Brake Booster Check Valve Replacement .
    â€¢ Damaged vacuum booster. Refer to Power Vacuum Brake Booster Replacement .
    â€¢ Restricted brake fluid passage. Inspect brake hose. Refer to Brake Hose Inspection .

Excessive Brake Pedal Effort

    â€¢ Leaking vacuum or booster system. Refer to Power Vacuum Brake Booster Replacement .
    â€¢ Restricted passage in the vacuum booster. Refer to Vacuum Brake Booster Hose Replacement .
    â€¢ Damaged vacuum booster. Refer to Power Vacuum Brake Booster Replacement .
    â€¢ Worn out brake lining. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Glazed brake lining. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Incorrect brake lining material. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Contaminated brake lining. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Brake lining damage by abuse. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Improper rotor surface finish. Refer to Brake Rotor Refinishing in Disc Brakes.
    â€¢ Restricted brake fluid passage. Refer to Brake Hose Inspection .
    â€¢ Brake pedal linkage interference or binding. Refer to Brake Pedal Replacement .
    â€¢ Operator riding the brake pedal.
    â€¢ Low engine vacuum. Check for leaks.
    â€¢ Restricted vacuum line to the booster. Refer to Vacuum Brake Booster Hose Replacement .
    â€¢ Excessive vehicle loading.

Excessive Braking Action

    â€¢ Damaged vacuum booster. Refer to Power Vacuum Brake Booster Replacement .
    â€¢ Worn out brake lining. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Uneven brake lining wear. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Incorrect brake lining material. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Brake lining damage by abuse. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Improper rotor surface finish. Refer to Brake Rotor Refinishing in Disc Brakes.
    â€¢ Scored rotor. Refer to Brake Rotor Refinishing in Disc Brakes.
    â€¢ Brake assembly attachments loose. Refer to Front Brake Caliper Bracket Replacement or Rear Brake Caliper Bracket Replacement in Disc Brakes.

Brakes Slow To Respond

    â€¢ Contaminated or improper brake fluid. Refer to Hydraulic Brake System Flushing .
    â€¢ Leaking vacuum or booster system. Refer to Power Vacuum Brake Booster Replacement .
    â€¢ Restricted passage in the vacuum booster. Refer to Vacuum Brake Booster Hose Replacement .
    â€¢ Damaged vacuum booster. Refer to Power Vacuum Brake Booster Replacement .
    â€¢ Worn out brake linings. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Glazed brake lining. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Incorrect lining material. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Improper rotor surface finish. Refer to Brake Rotor Refinishing in kDisc Brakes.
    â€¢ Restricted brake fluid passage. Refer to Brake Hose Inspection .
    â€¢ Brake pedal linkage interference or binding. Refer to Brake Pedal Replacement .
    â€¢ Sticking caliper or caliper pistons. Refer to Front Brake Caliper Overhaul or Rear Brake Caliper Overhaul in Disc Brakes.
    â€¢ Low engine vacuum. Check for leaks.
    â€¢ Restricted vacuum line to the booster. Refer to Vacuum Brake Booster Hose Replacement .

Brakes Slow To Release

    â€¢ Contaminated or improper brake fluid. Refer to Hydraulic Brake System Flushing .
    â€¢ Restricted passage in the vacuum booster. Refer to. Power Vacuum Brake Booster Replacement .
    â€¢ Damaged vacuum booster. Refer to Power Vacuum Brake Booster Replacement .
    â€¢ Restricted brake fluid passage. Refer to Brake Hose Inspection .
    â€¢ Brake pedal linkage interference or binding. Refer to Brake Fluid Leak .
    â€¢ Sticking caliper or caliper pistons. Refer to Front Brake Caliper Overhaul or Rear Brake Caliper Overhaul in Disc Brakes.
    â€¢ Parking brake not releasing. Refer to Park Brake Cable Service/Adjustment .
    â€¢ Caliper to knuckle clearance. Refer to Front Brake Caliper Bracket Replacement or Rear Brake Caliper Bracket Replacement in Disc Brakes.

Brakes Drag

    â€¢ Contaminated or improper brake fluid. Refer to Hydraulic Brake System Flushing .
    â€¢ Brake assembly attachments loose. Refer to Front Brake Caliper Bracket Replacement or Rear Brake Caliper Bracket Replacement in Disc Brakes.
    â€¢ Restricted brake fluid passage. Refer to Brake Hose Inspection .
    â€¢ Improperly adjusted stoplamp switch or cruise control vacuum dump. Refer to Stop Lamp Switch Adjustment .
    â€¢ Brake pedal linkage interference or binding. Refer to Brake Pedal Replacement .
    â€¢ Improperly adjusted parking brake. Refer to Park Brake Cable Service/Adjustment in Park Brake.
    â€¢ Loose front suspension parts. Refer to Suspension Component Inspection in Front Suspension.
    â€¢ Operator riding the brake pedal.
    â€¢ Sticking caliper or caliper pistons. Refer to Front Brake Caliper Overhaul or Rear Brake Caliper Overhaul in Disc Brakes.
    â€¢ Parking brake not releasing. Refer to Park Brake Cable Service/Adjustment in Park Brake.
    â€¢ Parking brake cables frozen. Refer to Park Brake Cable Service/Adjustment in Park Brake.
    â€¢ Parking brake cables corroded. Refer to Park Brake Cable Service/Adjustment in Park Brake.

Uneven Braking Action (Side to Side)

    â€¢ Leaking brake line or connection. Refer to Brake Fluid Leak .
    â€¢ Leaking piston. Refer to Front Brake Caliper Overhaul in Disc Brakes.
    â€¢ Contaminated or improper brake fluid. Refer to Hydraulic Brake System Flushing .
    â€¢ Worn out brake lining. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Uneven brake lining wear. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Incorrect brake lining material. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Contaminated brake lining. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Brake lining damage by abuse. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Improper rotor surface finish. Refer to Brake Rotor Refinishing in Disc Brakes.
    â€¢ Scored rotor. Refer to Brake Rotor Refinishing in Disc Brakes.
    â€¢ Brake assembly attachments loose. Refer to Front Brake Caliper Bracket Replacement or Rear Brake Caliper Bracket Replacement in Disc Brakes.
    â€¢ Restricted brake fluid passage. Refer to Brake Hose Inspection .
    â€¢ Incorrect front wheel alignment. Refer to Pre-Alignment Road Test with Customer in Wheel Alignment.
    â€¢ Incorrect tire pressure. Refer to Tire and Wheel Specifications in Tires and Wheels.
    â€¢ Loose front suspension parts. Refer to Suspension Component Inspection in Front Suspension.
    â€¢ Sticking caliper or caliper pistons. Refer to Front Brake Caliper Overhaul or Rear Brake Caliper Overhaul in Disc Brakes.
    â€¢ Parking brake not releasing. Refer to Park Brake Cable Service/Adjustment in Park Brake.
    â€¢ Caliper to knuckle clearance. Refer to Ball Stud and Knuckle Inspection in Front Suspensiion.

Uneven Braking Action (Front to Rear)

    â€¢ Leaking brake line or connection. Refer to Brake Fluid Leak .
    â€¢ Leaking piston. Refer to Front Brake Caliper Overhaul or Rear Brake Caliper Overhaul in Disc Brakes.
    â€¢ Leaking master cylinder (internal). Refer to Master Cylinder Overhaul .
    â€¢ Air in the brake system. Refer to Hydraulic Brake System Bleeding .
    â€¢ Contaminated or improper brake fluid. Refer to Hydraulic Brake System Flushing .
    â€¢ Worn out brake lining. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Uneven brake lining wear. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Glazed brake lining. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Incorrect brake lining material. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Contaminated brake lining. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Brake lining damage by abuse. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Improper rotor surface finish. Refer to Brake Rotor Refinishing in Disc Brakes.
    â€¢ Scored rotor. Refer to Brake Rotor Refinishing in Disc Brakes.
    â€¢ Brake assembly attachments loose. Refer to Front Brake Caliper Bracket Replacement or Rear Brake Caliper Bracket Replacement in Disc Brakes.
    â€¢ Restricted brake fluid passage. Refer to Brake Hose Inspection .
    â€¢ Improperly adjusted parking brake. Refer to Park Brake Cable Service/Adjustment in Park Brake.
    â€¢ Sticking caliper or caliper pistons. Refer to Front Brake Caliper Overhaul or Rear Brake Caliper Overhaul in Disc Brakes.
    â€¢ Improper rear brake adjustment. Refer to Park Brake Cable Service/Adjustment in Park Brake.
    â€¢ Excessive Vehicle Loading.

Scraping Noise From Brakes

    â€¢ Worn out brake lining. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Uneven brake lining wear. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Contaminated brake lining. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Brake lining damage by abuse. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Brake assembly attachments loose. Refer to Front Brake Caliper Bracket Replacement or Rear Brake Caliper Bracket Replacement in Disc Brakes.
    â€¢ Loose front suspension parts. Refer to Suspension Component Inspection in Front Suspension.

Brakes Squeak Without Application

    â€¢ Worn out brake lining. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Uneven brake lining wear. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Glazed brake lining. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Incorrect brake lining material. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Contaminated brake lining. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Brake lining damage by abuse. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Scored Rotor. Refer to Brake Rotor Refinishing in Disc Brakes.
    â€¢ Brake assembly attachments loose. Refer to Front Brake Caliper Bracket Replacement or Rear Brake Caliper Bracket Replacement in Disc Brakes.

Brakes Squeak During Application

    â€¢ Worn out brake lining. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Uneven brake lining wear. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Glazed brake lining. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Incorrect brake lining material. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Contaminated brake lining. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Brake lining damage by abuse. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Improper rotor surface finish. Refer to Brake Rotor Refinishing in Disc Brakes.
    â€¢ Scored rotor. Refer to Brake Rotor Refinishing in Disc Brakes.
    â€¢ Brake assembly attachments loose. Refer to Front Brake Caliper Bracket Replacement or Rear Brake Caliper Bracket Replacement in Disc Brakes.

Brakes Chatter (Roughness)

    â€¢ Contaminated brake lining. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Scored rotor. Refer to Brake Rotor Refinishing in Disc Brakes.
    â€¢ Improper thickness variation in rotor. Refer to Brake Rotor Tolerance in Disc Brakes.
    â€¢ Excessive lateral runout in rotor. Refer to Brake Rotor Lateral Runout Check in Disc Brakes.
    â€¢ Brake assembly attachments loose. Refer to Front Brake Caliper Bracket Replacement or Rear Brake Caliper Bracket Replacement in Disc Brakes.
    â€¢ Loose front suspension parts. Refer to Suspension Component Inspection in Front Suspension.
    â€¢ Out-of-balance wheel assembly. Refer to Pre-Alignment Road Test with Customer in Wheel Alignment.
    â€¢ Improperly torqued wheel nuts. Refer to Fastener Tightening Specifications in Tires And Wheels.
    â€¢ Poor rotor surface finish. Refer to Brake Rotor Refinishing in Disc Brakes.

Brakes Groan at the End of Stop

    â€¢ Worn out brake lining. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Incorrect lining material. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Contaminated brake lining. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Brake lining damage by abuse. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.

Brake Warning Lamp ON

    â€¢ Leaking brake line or connection. Refer to Brake Fluid Leak .
    â€¢ Leaking piston. Refer to Front Brake Caliper Overhaul or Rear Brake Caliper Overhaul in Disc Brakes.
    â€¢ Leaking master cylinder (internal). Refer to Master Cylinder Overhaul .
    â€¢ Air in brake system. Refer to Hydraulic Brake System Bleeding .
    â€¢ Contaminated or improper brake fluid. Refer to Hydraulic Brake System Flushing .
    â€¢ Worn out brake lining. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Uneven brake lining wear. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Parking brake switch circuit grounded. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
    â€¢ Parking brake not releasing. Refer to Park Brake Cable Service/Adjustment in Park Brake.
    â€¢ Low brake fluid. Refer to Master Cylinder Reservoir Filling .

Premature Lining Wear Out

    â€¢ Incorrect lining material. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Brake lining damaged by abuse. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Scored rotor. Refer to Brake Rotor Refinishing in Disc Brakes.
    â€¢ Brake assembly attachments loose. Refer to Front Brake Caliper Bracket Replacement or Rear Brake Caliper Bracket Replacement in Disc Brakes.
    â€¢ Improperly adjusted stoplamp switch or cruise control vacuum dump. Refer to Stop Lamp Switch Adjustment .
    â€¢ Brake pedal linkage interference or binding. Refer to Brake Pedal Bracket Replacement .
    â€¢ Operator riding the brake pedal.
    â€¢ Sticking caliper or caliper pistons. Refer to Front Brake Caliper Overhaul or Rear Brake Caliper Overhaul in Disc Brakes.
    â€¢ Parking brake not releasing. Refer to Park Brake Cable Service/Adjustment in Park Brake.

Parking Brake Won't Hold

    â€¢ Worn out park brake lining. Refer to Parking Brake Shoe Replacement in Park Brake.
    â€¢ Uneven park brake lining wear. Refer to Parking Brake Shoe Replacement in Park Brake.
    â€¢ Incorrect park brake lining material. Refer to Parking Brake Shoe Replacement in Park Brake.
    â€¢ Contaminated park brake lining. Refer to Parking Brake Shoe Replacement in Park Brake.
    â€¢ Park brake lining damaged by abuse. Refer to Parking Brake Shoe Replacement in Park Brake.
    â€¢ Park brake assembly attachments loose. Refer to Parking Brake Shoe Replacement in Park Brake.
    â€¢ Improperly adjusted parking brake. Refer to Park Brake Cable Service/Adjustment in Park Brake.
    â€¢ Improper park brake adjustment. Refer to Park Brake Cable Service/Adjustment in Park Brake.
    â€¢ Excessive vehicle loading.
    â€¢ Parking brake cables frozen. Refer to Park Brake Cable Service/Adjustment in Park Brake.
    â€¢ Parking brake cables corroded. Refer to Park Brake Cable Service/Adjustment in Park Brake.

Parking Brake Won't Release

    â€¢ Improperly adjusted parking brake. Refer to Park Brake Cable Service/Adjustment in Park Brake.
    â€¢ Parking brake cables frozen. Refer to Park Brake Cable Service/Adjustment in Park Brake.
    â€¢ Parking brake cables corroded. Refer to Park Brake Cable Service/Adjustment in Park Brake.

Brake Pulsation

    â€¢ Worn out brake lining. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Incorrect lining material. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Contaminated brake lining. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Brake linings damaged by abuse. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Scored rotor. Refer to Brake Rotor Refinishing in Disc Brakes.
    â€¢ Improper thickness variation in rotor. Refer to Brake Rotor Tolerance in Disc Brakes.
    â€¢ Excessive lateral runout in rotor. Refer to Brake Rotor Lateral Runout Check in Disc Brakes.
    â€¢ Out-of-balance wheel assembly. Refer to Pre-Alignment Road Test with Customer in Wheel Alignment.
    â€¢ Improperly torqued wheel nuts. Refer to Fastener Tightening Specifications in Tires And Wheels.
    â€¢ Poor drum surface finish. Refer to Brake Rotor Refinishing in Disc Brakes.

Brake Pulls

    â€¢ Leaking brake line or connection. Refer to Brake Fluid Leak .
    â€¢ Leaking piston. Refer to Front Brake Caliper Overhaul or Rear Brake Caliper Overhaul in Disc Brakes.
    â€¢ Uneven brake lining wear. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Incorrect lining material. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Contaminated brake lining. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Brake linings damaged by abuse. Refer to Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.
    â€¢ Improper rotor surface finish. Refer to Brake Rotor Refinishing in Disc Brakes.
    â€¢ Incorrect front wheel alignment. Refer to Pre-Alignment Road Test with Customer in Wheel Alignment.
    â€¢ Incorrect tire pressure. Refer to Tire and Wheel Specifications in Tires and Wheels.
    â€¢ Loose front suspension parts. Refer to Suspension Component Inspection in Front Suspension.
    â€¢ Caliper to knuckle clearance. Refer to Ball Stud and Knuckle Inspection in Front Suspension.