Brakes Symptom Diagnosis
BRAKES SYMPTOM DIAGNOSIS
| Condition | Possible Cause | Action |
|---|---|---|
| Not enough braking force | Brake fluid leakage from brake lines | Locate leaking point and repair . |
| Brake disc or pad stained with fluid, grease or other oil | Clean or replace . | |
| Overheated brakes | Determine cause and repair . | |
| Poor contact of shoes on brake drum (rear drum brake model) | Repair for proper contact . | |
| Brake shoe stained with oil or wet with water (rear drum brake model) | Replace . | |
| Badly worn brake pad | Replace . | |
| Defective wheel cylinders (rear drum brake model) | Repair or replace . | |
| Malfunctioning caliper assembly | Repair or replace . | |
| Air in system | Bleed system . | |
| Brake booster internal failure | Replace brake booster . | |
| Negative pressure for brake booster is inadequate | Check engine condition and vacuum hose . | |
| Malfunctioning ABS (ESP®) | Check system and replace as necessary . | |
| Brake pull (Brakes not working in unison) | Pad, disc, shoe and/or drum are wet with water or stained with oil in some brakes | Clean or replace . |
| Drum-to-shoe clearance out of adjustment in some brakes (Malfunctioning auto adjusting mechanism) (rear drum brake model) | Check for inoperative auto adjusting mechanism . | |
| Disc and/or drum are out of round in some brakes | Replace . | |
| Tires are inflated unequally | Inflate equally . | |
| Malfunction in wheel cylinders (rear drum brake model) | Repair or replace . | |
| Disturbed front wheel alignment | Adjust as prescribed . | |
| Unmatched tires on same axle | Tires with approximately the same amount of tread should be used on the same axle . | |
| Restricted brake pipes or hoses | Check for soft hoses and damaged lines. Replace with new hoses and new double walled steel brake tubing . | |
| Malfunctioning caliper assembly | Check for stuck or sluggish pistons and proper lubrication of caliper slide pin . | |
| Loose suspension parts | Check all suspension mountings . | |
| Loose calipers | Check and torque bolts to specifications . | |
| Noise (High pitched squeak without brake applied) | Contact wear indicator to brake disc | Replace brake pad . |
| Worn rear brake shoe (rear drum brake model) | Replace brake shoe . | |
| Excessive pedal travel (Pedal stroke too large) | Partial brake system failure | Check brake systems and repair as necessary . |
| Brake fluid leaking | Repair the leaking point, and bleed air . | |
| Air in system (soft/spongy pedal) | Bleed system . | |
| Rear brake system not adjusted (malfunctioning auto adjusting mechanism) (rear drum brake model) | Repair auto adjusting mechanism . | |
| Bent brake shoes (rear drum brake model) | Replace brake shoes . | |
| Brake locked | Malfunctioning ABS (ESP®) | Check system referring to ABS CHECKor ELECTRONIC STABILITY PROGRAM CHECK . |
| Dragging brakes (A very light drag is present in all brakes immediately after pedal is released) | Master cylinder pistons not returning correctly | Replace master cylinder . |
| Restricted brake pipes or hoses | Check for soft hoses or damaged pipes and replace with new hoses and/or new brake piping . | |
| Incorrect parking brake adjustment on rear brakes | Check and adjust to correct specifications . | |
| Weakened or broken return springs in the brake | Replace . | |
| Sluggish parking brake cables or linkage | Repair or replace . | |
| Wheel cylinder or caliper piston sticking | Repair as necessary . | |
| Badly worn piston seal in caliper | Replace piston seal . | |
| Improper brake pedal free height | Check brake pedal free height . | |
| Pedal pulsation (Pedal pulsates when depressed for braking) | Damaged wheel bearings | Replace wheel bearings . |
| Distorted steering knuckle or rear wheel spindle or rear axle shaft | Replace knuckle or rear wheel spindle or rear axle shaft . | |
| Excessive disc lateral runout | Check per instructions. If not within specifications, replace or machine disc . | |
| Rear drums out of round (rear drum brake model) | Check runout . | |
| Braking noise | Glazed brake pad and/or brake shoe | Repair or replace brake pad and/or brake shoe . |
| Worn or distorted brake shoe (rear drum brake model) | Replace brake shoe . | |
| Loose front wheel bearings | Replace wheel hub . | |
| Distorted backing plates or loose mounting bolts | Replace or retighten securing bolts . | |
| Contact wear indicator to brake disc | Replace brake pads . | |
| Brake warning light lights after engine start | Parking brake applied | Release parking brake and check that brake warning light turns off . |
| Insufficient amount of brake fluid | Investigate leaky point, correct it and add brake fluid . | |
| Brake fluid leaking | Investigate leaky point, correct it and add brake fluid . | |
| Brake warning light circuit faulty | Repair circuit . | |
| Malfunctioning EBD system | Check system referring to EBD WARNING LIGHT (BRAKE WARNING LIGHT) COMES ON STEADY . | |
| Brake warning light turns on when brake is applied | Brake fluid leaking | Investigate leaky point, correct it and add brake fluid . |
| Insufficient amount of brake fluid | Investigate leaky point, correct it and add brake fluid . | |
| Brake warning light fails to turn on even when parking brake is applied | Brake warning light circuit faulty | Replace bulb or repair circuit . |
| ABS warning light or ESP® warning light turns on after engine start | Malfunctioning ABS (ESP®) | Check system referring to ABS CHECKor ELECTRONIC STABILITY PROGRAM CHECK . |
| ABS warning light or ESP® warning light turns on when brake is applied | Malfunctioning ABS (ESP®) | Check system referring to ABS CHECKor ELECTRONIC STABILITY PROGRAM CHECK . |
| ABS warning light or ESP® warning light does not turn on for 2 sec. after ignition switch has turned ON | Bulb burnt out | Replace bulb . |
| Malfunctioning ABS (ESP®) | Check system referring to ABS CHECKor ELECTRONIC STABILITY PROGRAM CHECK . | |
| ABS warning light flashes | New ABS (ESP®) hydraulic unit/control module assembly installed. | Perform ABS HYDRAULIC UNIT OPERATION CHECKor ESP® HYDRAULIC UNIT OPERATION CHECK . |