Brake System Diagnosis. Pontiac Firebird 1998

For 1990-2009 cars only

Makes 🢒 Pontiac 🢒 1998 🢒 Firebird 🢒 Brakes 🢒 Hydraulic Brakes 🢒 Brake System Diagnosis

Symptom

Causes

Improper Brake Pedal Travel

•	Leaking brake line or connection. Refer to Brake Fluid Leak .

•	Leaking piston seal. Refer to Brake Caliper Overhaul .

•	Leaking master cylinder (internal). Replace the master cylinder. Refer to Master Cylinder Replacement .

•	Air in brake system. Refer to Hydraulic Brake System Bleeding .

•	Contaminated or improper brake fluid. Refer to Brake Fluid and Brake Fluid Handling .

•	Leaking vacuum or booster system. Refer to Power Vacuum Brake Booster Replacement .

•	Damaged vacuum booster. Refer to Power Vacuum Brake Booster Replacement .

•	Uneven brake lining wear. Refer to Brake Pad Inspection in Disc Brakes.

•	Brake lining damage by abuse. Refer to Brake Pad Inspection in Disc Brakes.

•	Improper thickness variation in rotor. Refer to Brake Rotor Thickness Variation Check .

•	Excessive lateral runout in rotor. Refer to Brake Rotor Lateral Runout Check .

•	Brake assembly attachments loose (including splash shield). Refer to Brake Caliper Inspection in Disc Brakes.

•	Improperly adjusted stoplamp switch or cruise control vacuum dump. Refer to Stop Lamp Switch Adjustment .

•	Incorrect vacuum booster pushrod length. Refer to Power Vacuum Brake Booster Replacement in Hydraulic Brakes.

•	Low brake fluid. Refer to Master Cylinder Reservoir Filling .

•	Improper rear brake adjustment. Refer to Parking Brake Shoe Adjustment in Park Brake.

•	Low engine vacuum. Refer to Engine Compression Test in Engine Mechanical-3.8L or Engine Compression Test in Engine Mechanical-5.7L.

Brake Pedal Travel Gradually Increases

•	Leaking brake line or connection. Refer to Brake Fluid Leak .

•	Leaking piston seal. Refer to Brake Caliper Overhaul .

•	Leaking master cylinder (internal). Replace master cylinder. Refer to Master Cylinder Replacement .

•	Restricted passage in the vacuum booster. Refer to Power Vacuum Brake Booster Replacement .

•	Damaged vacuum booster. Refer to Power Vacuum Brake Booster Replacement .

•	Restricted brake fluid passage. Refer to Hydraulic Brake System Flushing in Hydraulic Brakes.

Excessive Brake Pedal Effort

•	Leaking vacuum or booster system. Refer to Power Vacuum Brake Booster Replacement in Hydraulic Brakes.

•	Restricted passage in the vacuum booster. Refer to Power Vacuum Brake Booster Replacement in Hydraulic Brakes.

•	Damaged vacuum booster. Refer to Power Vacuum Brake Booster Replacement .

•	Worn out brake lining. Refer to Brake Pad Inspection in Disc Brakes.

•	Glazed brake lining. Refer to Brake Pad Inspection in Disc Brakes.

•	Incorrect brake lining material. Refer to Brake Pad Inspection in Disc Brakes.

•	Contaminated brake lining. Refer to Brake Pad Inspection in Disc Brakes.

•	Brake lining damage by abuse. Refer to Brake Pad Inspection in Disc Brakes.

•	Improper rotor surface finish. Refer to Brake Rotor Refinishing in Disc Brakes.

•	Restricted brake fluid passage. Refer to Hydraulic Brake System Flushing in Hydraulic Brakes.

•	Brake pedal linkage interference or binding. Refer to Brake Pedal Travel in Hydraulic Brakes.

•	Operator riding the brake pedal. Refer to Brake Pad Inspection in Disc Brakes.

•	Low engine vacuum. Refer to Engine Compression Test in Engine Mechanical-3.8 L or Engine Compression Test in Engine Mechanical-5.7L.

•	Excessive vehicle loading. Refer to Brake Pad Inspection in Disc Brakes.

•	Rotor corroded. Refer to Brake Caliper Inspection in Disc Brakes.

•	ABS modulator RR piston seized. Refer to Brake Pressure Modulator Valve Replacement in Antilock Brake System.

Excessive Braking Action

•	Damaged vacuum booster. Refer to Power Vacuum Brake Booster Replacement .

•	Worn out brake lining. Refer to Brake Pad Inspection in Disc Brakes.

•	Uneven brake lining wear. Refer to Brake Pad Inspection in Disc Brakes.

•	Incorrect brake lining material. Refer to Brake Pad Inspection in Disc Brakes.

•	Brake lining damage by abuse. Refer to Brake Pad Inspection in Disc Brakes.

•	Improper rotor surface finish. Refer to Brake Rotor Refinishing in Disc Brakes.

•	Scored rotor. Refer to Brake Rotor Refinishing .

•	Brake assembly attachments loose (including splash shield). Refer to Brake Caliper Inspection in Disc Brakes.

•	Poor drum surface finish.

Brakes Slow To Respond

•	Air in the brake system. Refer to Hydraulic Brake System Bleeding .

•	Contaminated or improper brake fluid. Refer to Brake Fluid and Brake Fluid Handling .

•	Leaking vacuum or booster system. Refer to Power Vacuum Brake Booster Replacement in Hydraulic Brakes.

•	Restricted passage in the vacuum booster. Refer to Power Vacuum Brake Booster Replacement in Hydraulic Brakes.

•	Damaged vacuum booster. Refer to Power Vacuum Brake Booster Replacement .

•	Glazed brake lining. Refer to Brake Pad Inspection in Disc Brakes.

•	Restricted brake fluid passage. Refer to Hydraulic Brake System Flushing in Hydraulic Brakes.

•	Brake pedal linkage interference or binding. Refer to Brake Pedal Travel in Hydraulic Brakes.

•	Sticking caliper or caliper pistons. Refer to Brake Caliper Overhaul .

•	Low engine vacuum. Refer to Engine Compression Test in Engine Mechanical-3.8 L or Engine Compression Test in Engine Mechanical-5.7L.

Brakes Slow To Release

•	Contaminated or improper brake fluid. Refer to Brake Fluid and Brake Fluid Handling .

•	Restricted passage in the vacuum booster. Refer to Power Vacuum Brake Booster Replacement in Hydraulic Brakes.

•	Damaged vacuum booster. Refer to Power Vacuum Brake Booster Replacement .

•	Restricted brake fluid passage. Refer to Hydraulic Brake System Flushing in Hydraulic Brakes.

•	Brake pedal linkage interference or binding. Refer to Brake Pedal Travel in Hydraulic Brakes.

•	Sticking caliper or caliper pistons. Refer to Brake Caliper Overhaul .

•	Parking brake not releasing. Refer to Parking Brake Shoe Adjustment in Park Brake.

•	Caliper to knuckle clearance. Refer to Brake Caliper Inspection in Disc Brakes.

Brakes Drag

•	Contaminated or improper brake fluid. Refer to Brake Fluid and Brake Fluid Handling .

•	Brake lining damage by abuse. Refer to Brake Pad Inspection in Disc Brakes.

•	Excessive lateral runout in rotor. Refer to Brake Rotor Lateral Runout Check a.

•	Brake assembly attachments loose (including splash shield). Refer to Brake Caliper Inspection in Disc Brakes.

•	Restricted brake fluid passage. Refer to Hydraulic Brake System Flushing in Hydraulic Brakes.

•	Improperly adjusted stoplamp switch or cruise control vacuum dump. Refer to Stop Lamp Switch Adjustment .

•	Brake pedal linkage interference or binding. Refer to Brake Pedal Travel in Hydraulic Brakes.

•	Incorrect vacuum booster pushrod length. Refer to Power Vacuum Brake Booster Replacement in Hydraulic Brakes.

•	Loose front suspension parts. Refer to Front Suspension Components in Front Suspension.

•	Operator riding the brake pedal. Refer to Brake Pad Inspection in Disc Brakes.

•	Sticking caliper or caliper pistons. Refer to Brake Caliper Overhaul .

•	Parking brake not releasing. Refer to Parking Brake Shoe Adjustment in Park Brake.

•	Caliper to knuckle clearance. Refer to Brake Caliper Inspection in Disc Brakes.

•	Improper rear brake adjustment. Refer to Parking Brake Shoe Adjustment in Park Brake.

•	Parking brake cables seized. Refer to Parking Brake Shoe Adjustment in Park Brake.

Uneven Braking Action (Side to Side)

•	Contaminated or improper brake fluid. Refer to Brake Fluid and Brake Fluid Handling .

•	Worn out brake lining. Refer to Brake Pad Inspection in Disc Brakes.

•	Uneven brake lining wear. Refer to Brake Pad Inspection in Disc Brakes.

•	Glazed brake lining. Refer to Brake Pad Inspection in Disc Brakes.

•	Incorrect brake lining material. Refer to Brake Pad Inspection in Disc Brakes.

•	Contaminated brake lining. Refer to Brake Pad Inspection in Disc Brakes.

•	Brake lining damage by abuse. Refer to Brake Pad Inspection in Disc Brakes.

•	Improper rotor surface finish. Refer to Brake Rotor Refinishing in Disc Brakes.

•	Scored rotor. Refer to Brake Rotor Refinishing .

•	Brake assembly attachments loose (including splash shield). Refer to Brake Caliper Inspection in Disc Brakes.

•	Restricted brake fluid passage. Refer to Hydraulic Brake System Flushing in Hydraulic Brakes.

•	Incorrect front wheel alignment. Refer to Preliminary Alignment Inspection in Wheel Alignment.

•	Incorrect tire pressure. Refer to Tire and Wheel Specifications in Tires and Wheels.

•	Loose front suspension parts. Refer to Front Suspension Components in Front Suspension.

•	Sticking caliper or caliper pistons. Refer to Brake Caliper Overhaul .

•	Parking brake not releasing. Refer to Parking Brake Shoe Adjustment in Park Brake.

•	Caliper to knuckle clearance. Refer to Brake Caliper Inspection in Disc Brakes.

•	Rotor corroded. Refer to Brake Rotor Refinishing in Disc Brakes.

Uneven Braking Action (Front to Rear)

•	Leaking brake line or connection. Refer to Brake Fluid Leak .

•	Leaking piston seal. Refer to Brake Caliper Overhaul .

•	Leaking master cylinder (internal). Replace master cylinder. Refer to Master Cylinder Replacement .

•	Air in brake system. Refer to Hydraulic Brake System Bleeding .

•	Contaminated or improper brake fluid. Refer to Brake Fluid and Brake Fluid Handling .

•	Worn out brake lining. Refer to Brake Pad Inspection in Disc Brakes.

•	Uneven brake lining wear. Refer to Brake Pad Inspection in Disc Brakes.

•	Glazed brake lining. Refer to Brake Pad Inspection in Disc Brakes.

•	Incorrect brake lining material. Refer to Brake Pad Inspection in Disc Brakes.

•	Contaminated brake lining. Refer to Brake Pad Inspection in Disc Brakes.

•	Brake lining damage by abuse. Refer to Brake Pad Inspection in Disc Brakes.

•	Improper rotor surface finish. Refer to Brake Rotor Refinishing in Disc Brakes.

•	Scored rotor. Refer to Brake Rotor Refinishing .

•	Brake assembly attachments loose (including splash shield). Refer to Brake Caliper Inspection in Disc Brakes.

•	Restricted brake fluid passage. Refer to Hydraulic Brake System Flushing in Hydraulic Brakes.

•	Sticking caliper or caliper pistons. Refer to Brake Caliper Overhaul .

•	Low brake fluid. Refer to Master Cylinder Reservoir Filling .

•	Improper rear brake adjustment. Refer to Parking Brake Shoe Adjustment in Park Brake.

•	Excessive Vehicle Loading. Refer to Brake Pad Inspection in Disc Brakes.

•	ABS modulator RR piston seized. Refer to Brake Pressure Modulator Valve Replacement in Antilock Brake System.

Scraping Noise from Brakes

•	Worn out brake lining. Refer to Brake Pad Inspection in Disc Brakes.

•	Uneven brake lining wear. Refer to Brake Pad Inspection in Disc Brakes.

•	Contaminated brake lining. Refer to Brake Pad Inspection in Disc Brakes.

•	Brake lining damage by abuse. Refer to Brake Pad Inspection in Disc Brakes.

•	Brake assembly attachments loose (including splash shield). Refer to Brake Caliper Inspection in Disc Brakes.

•	Loose front suspension parts. Refer to Front Suspension Components in Front Suspension.

•	Rotor corroded. Refer to Brake Rotor Refinishing in Disc Brakes.

Brakes Squeak without Application

•	Worn out brake lining. Refer to Brake Pad Inspection in Disc Brakes.

•	Uneven brake lining wear. Refer to Brake Pad Inspection in Disc Brakes.

•	Glazed brake lining. Refer to Brake Pad Inspection in Disc Brakes.

•	Incorrect brake lining material. Refer to Brake Pad Inspection in Disc Brakes.

•	Contaminated brake lining. Refer to Brake Pad Inspection in Disc Brakes.

•	Brake lining damage by abuse. Refer to Brake Pad Inspection in Disc Brakes.

•	Scored Rotor. Refer to Brake Rotor Refinishing .

•	Improperly adjusted stoplamp switch or cruise control vacuum dump. Refer to Stop Lamp Switch Adjustment .

•	Incorrect vacuum booster pushrod length. Refer to Power Vacuum Brake Booster Replacement in Hydraulic Brakes.

•	Sticking caliper or caliper pistons. Refer to Brake Caliper Inspection in Disc Brakes.

•	Caliper to knuckle clearance. Refer to Brake Caliper Inspection in Disc Brakes.

Brakes Squeak During Application

•	Worn out brake lining. Refer to Brake Pad Inspection in Disc Brakes.

•	Uneven brake lining wear. Refer to Brake Pad Inspection in Disc Brakes.

•	Glazed brake lining. Refer to Brake Pad Inspection in Disc Brakes.

•	Incorrect brake lining material. Refer to Brake Pad Inspection in Disc Brakes.

•	Contaminated brake lining. Refer to Brake Pad Inspection in Disc Brakes.

•	Brake lining damage by abuse. Refer to Brake Pad Inspection in Disc Brakes.

•	Scored rotor. Refer to Brake Rotor Refinishing .

•	Brake assembly attachments loose (including splash shield). Refer to Brake Caliper Inspection in Disc Brakes.

•	Excessive vehicle loading. Refer to Brake Pad Inspection in Disc Brakes.

Brakes Chatter (Roughness)

•	Scored rotor. Refer to Brake Caliper Inspection in Disc Brakes.

•	Improper thickness variation in rotor. Refer to Brake Rotor Thickness Variation Check .

•	Excessive lateral runout in rotor. Refer to Brake Rotor Lateral Runout Check .

•	Brake assembly attachments loose (including splash shield). Refer to Brake Caliper Inspection in Disc Brakes.

•	Loose front suspension parts. Refer to DTC P0138 HO2S Circuit High Voltage Sensor 2 in Front Suspension.

•	Out-of-balance wheel assembly. Refer to Tire and Wheel Balancing in Vibration Diagnosis and Correction.

•	Improperly torqued wheel nuts. Refer to Wheel Installation in Tires and Wheels.

•	Poor drum surface finish.

•	Rotor corroded. Refer to Brake Pad Inspection in Hydraulic Brakes.

•	Grease or dirt on the rotor. Refer to Brake Pad Inspection in Disc Brakes.

Brakes Groan at the End of Stop

•	Incorrect lining material. Refer to Brake Pad Inspection in Disc Brakes.

•	Contaminated brake lining. Refer to Brake Pad Inspection in Disc Brakes.

•	Brake lining damage by abuse. Refer to Brake Pad Inspection in Disc Brakes.

•	Grease or dirt on the rotor. Refer to Brake Pad Inspection in Disc Brakes.

Brake Warning Lamp ON

•	Leaking brake line or connection. Refer to Brake Fluid Leak .

•	Leaking piston seal. Refer to Brake Caliper Overhaul .

•	Leaking master cylinder (internal). Replace master cylinder. Refer to Master Cylinder Replacement .

•	Air in brake system. Refer to Hydraulic Brake System Bleeding .

•	Contaminated or improper brake fluid. Refer to Brake Fluid and Brake Fluid Handling .

•	Parking brake switch circuit grounded. Refer to Park Brake Lever Assembly Replacement in Park Brake.

•	Parking brake not releasing. Refer to Parking Brake Shoe Adjustment in Park Brake.

•	Low brake fluid. Refer to Master Cylinder Reservoir Filling .

Premature Lining Wear Out

•	Leaking brake line or connection. Refer to Brake Fluid Leak .

•	Incorrect lining material. Refer to Brake Pad Inspection in Disc Brakes.

•	Brake lining damaged by abuse. Refer to Brake Pad Inspection in Disc Brakes.

•	Improperly adjusted stoplamp switch or cruise control vacuum dump. Refer to Stop Lamp Switch Adjustment .

•	Brake pedal linkage interference or binding. Refer to Brake Pedal Travel in Hydraulic Brakes.

•	Incorrect vacuum booster pushrod length. Refer to Power Vacuum Brake Booster Replacement in Hydraulic Brakes.

•	Operator riding brake pedal. Refer to Brake Pad Inspection in Disc Brakes.

•	Sticking caliper or caliper pistons. Refer to Brake Caliper Overhaul .

•	Parking brake not releasing. Refer to Parking Brake Shoe Adjustment in Park Brake.

•	Caliper to knuckle clearance. Refer to Brake Caliper Inspection in Disc Brakes.

•	Improper rear brake adjustment. Refer to Parking Brake Shoe Adjustment in Park Brake.

•	Excessive vehicle loading. Refer to Brake Pad Inspection in Disc Brakes.

•	Parking brake cable seized. Refer to Parking Brake Shoe Adjustment in Park Brake.

•	ABS modulator RR piston seized. Refer to Brake Pressure Modulator Valve Replacement in Antilock Brake System.

Parking Brake Won't Hold

•	Worn out brake lining. Refer to Brake Pad Inspection in Disc Brakes.

•	Uneven brake lining wear. Refer to Brake Pad Inspection in Disc Brakes.

•	Incorrect lining material. Refer to Brake Pad Inspection in Disc Brakes.

•	Contaminated brake lining. Refer to Brake Pad Inspection in Disc Brakes.

•	Brake lining damaged by abuse. Refer to Brake Pad Inspection in Disc Brakes.

•	Improper rotor surface finish. Refer to Brake Rotor Refinishing in Disc Brakes.

•	Sticking caliper or caliper pistons. Refer to Brake Caliper Overhaul .

•	Parking brake cables seized. Refer to Parking Brake Shoe Adjustment in Park Brake.

Parking Brake Won't Release

•	Sticking caliper or caliper pistons. Refer to Brake Caliper Overhaul .

•	Parking brake cables seized. Refer to Parking Brake Shoe Adjustment in Park Brake.

Brake Pulsation

•	Incorrect lining material. Refer to Brake Pad Inspection in Disc Brakes.

•	Contaminated brake lining. Refer to Brake Pad Inspection in Disc Brakes.

•	Brake linings damaged by abuse. Refer to Brake Pad Inspection in Disc Brakes.

•	Scored rotor. Refer to Brake Rotor Refinishing .

•	Improper thickness variation in rotor. Refer to Brake Rotor Thickness Variation Check .

•	Excessive lateral runout in rotor. Refer to Brake Rotor Lateral Runout Check .

•	Loose front suspension parts. Refer to DTC P0138 HO2S Circuit High Voltage Sensor 2 in Front Suspension.

•	Out-of-balance wheel assembly. Refer to Tire and Wheel Balancing in Vibration Diagnosis and Correction.

•	Improperly torqued wheel nuts. Refer to Wheel Installation in Tires and Wheels.

•	Poor drum surface finish.

•	Rotor corroded. Refer to Brake Rotor Refinishing in Hydraulic Brakes.

Brake Pulls

•	Worn out brake lining. Refer to Brake Pad Inspection in Disc Brakes.

•	Uneven brake lining wear. Refer to Brake Pad Inspection in Disc Brakes.

•	Incorrect lining material. Refer to Brake Pad Inspection in Disc Brakes.

•	Contaminated brake lining. Refer to Brake Pad Inspection in Disc Brakes.

•	Brake linings damaged by abuse. Refer to Brake Pad Inspection in Disc Brakes.

•	Improper rotor surface finish. Refer to Brake Rotor Refinishing in Hydraulic Brakes.

•	Scored rotor. Refer to Brake Rotor Refinishing .

•	Restricted brake fluid passage. Refer to Hydraulic Brake System Flushing in Hydraulic Brakes.

•	Incorrect front wheel alignment. Refer to Preliminary Alignment Inspection in Wheel Alignment.

•	Incorrect tire pressure. Refer to Tire and Wheel Specifications in Tires and Wheels.

•	Loose front suspension parts. Refer to Front Suspension Components in Front Suspension.

•	Sticking caliper or caliper pistons. Refer to Brake Caliper Overhaul .

•	Caliper to knuckle clearance. Refer to Brake Caliper Inspection in Disc Brakes.

•	Rotor corroded. Refer to Brake Rotor Refinishing in Disc Brakes.