Brakes Symptom Diagnosis
BRAKES SYMPTOM DIAGNOSIS
| Condition | Possible cause | Correction / Reference Item> |
|---|---|---|
| Not enough braking force | Brake oil leakage from brake lines | Locate leaking point and repair. |
| Brake disc or pads stained with oil | Clean or replace. | |
| Overheated brakes | Determine cause and repair. | |
| Poor contact of shoes on brake drum | Repair for proper contact. | |
| Brake shoes linings stained with oil or wet with water | Replace. | |
| Badly worn brake pad linings | Replace. | |
| Defective wheel cylinders | Repair or replace. | |
| Malfunctioning caliper assembly | Repair or replace. | |
| Air in system | Bleed system. | |
| Malfunctioning ABS (Antilock brake system), if equipped | Check system and replace as necessary. | |
| Brake pull (Brakes not working in unison) | Pad linings and/or shoe linings are wet with water or stained with oil in some brakes | Replace. |
| Drum-to-shoe clearance out of adjustment in some brakes (Malfunctioning auto adjusting mechanism) | Check for inoperative auto adjusting mechanism. | |
| Disc and/or drum is out of round in some brakes | Replace. | |
| Tires are inflated unequally | Inflate equally. | |
| Malfunction in wheel cylinders | 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 | Caliper should slide. 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) | Front lining worn out | Replace linings. |
| Contact wear indicator to brake disc | Replace pads. | |
| Excessive pedal travel (Pedal stroke too large) | Partial brake system failure | Check brake systems and repair as necessary. |
| Insufficient fluid in master cylinder reservoirs | Check warning light. Bleed system if required. Check for leaks and air in brake system. Fill reservoirs with approved brake fluid. | |
| Air in system (soft / spongy pedal) | Bleed system. | |
| Rear brake system not adjusted (malfunctioning auto adjusting mechanism) | Adjust rear brakes. Repair auto adjusting mechanism. |
|
| Bent brake shoes | Replace brake shoes. | |
| Worn rear brake shoes | Replace brake shoes. | |
| Brake locked (For vehicle equipped with ABS) | Malfunctioning ABS | Check system referring to ABS 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 or loose wheel bearings | Replace wheel bearings. |
| Distorted steering knuckle or rear wheel spindle | Replace knuckle or rear wheel spindle. | |
| Excessive disc lateral runout | Check per instructions. If not within specifications, replace or machine disc. | |
| Parallelism between pad and disc not within specifications | Check per instructions. If not within specifications, replace or machine disc. | |
| Rear drums out of round | Repair or replace drum as necessary. Check runout. | |
| Braking noise | Glazed shoe linings, or foreign matters stuck to linings | Repair or replace shoe linings. |
| Worn or distorted shoe linings | Replace shoe lining (or pad). | |
| Loose front wheel bearings | Replace wheel bearings. | |
| Distorted backing plates or loose mounting bolts | Replace or retighten securing bolts. | |
| Contact wear indicator to brake disc | Replace pads. | |
| Brake warning lamp lights after engine start | Parking brake applied | Release parking brake and check that brake warning lamp turns off. |
| Insufficient amount of brake fluid | Add brake fluid. | |
| Brake fluid leaking from brake line | Investigate leaky point, correct it and add brake fluid. | |
| Brake warning lamp circuit faulty | Repair circuit. | |
| Malfunctioning EBD system, if equipped with ABS. | Check system referring to EBD WARNING LAMP (BRAKE WARNING LAMP) COMES ON STEADY . | |
| Brake warning lamp turns on when brake is applied | Brake fluid leaking from brake line | Investigate leaky point, correct it and add brake fluid. |
| Insufficient amount of brake fluid | Add brake fluid. | |
| Brake warning lamp fails to turn on even when parking brake is applied | Brake warning lamp circuit faulty | Replace bulb or repair circuit. |
| ABS warning lamp turns on after engine start (If equipped) | Malfunctioning ABS | Check system referring to ABS CHECK . |
| ABS warning lamp turns on when brake is applied (If equipped) | Malfunctioning ABS | Check system referring to ABS CHECK . |
| ABS warning lamp does not turn on for 2 sec. after ignition switch has turned ON (If equipped) | Bulb burnt out | Replace bulb. |
| Malfunctioning ABS | Check system referring to ABS CHECK . | |
| ABS warning lamp flashes (If equipped) | New ABS hydraulic unit / control module assembly installed. | Perform ABS HYDRAULIC UNIT OPERATION CHECK . |