Symptom
| Cause
|
Excessive brake
pedal travel
|
| • | Leaking brake line or connection |
| • | Leaking wheel cylinder or piston seal |
| • | Leaking master cylinder |
| • | Uneven brake lining wear |
| • | Incorrect lining material |
| • | Excessive lateral runout |
| • | Faulty automatic adjusters |
| • | Incorrect wheel cylinder sizes |
| • | Missing or loose brake assembly attachments |
| • | Incorrect wheel bearing runout |
| • | Operator riding brake pedal |
| • | Improper booster pushrod length |
| • | Caliper not sliding freely |
|
Brake pedal travel gradually increases
|
| • | Leaking brake line or connection |
| • | Leaking wheel cylinder or piston seal |
| • | Leaking master cylinder |
| • | Restricted brake fluid passage or sticking wheel cylinder piston |
| • | Incorrect stoplamp switch adjustment |
| • | Operator riding brake pedal |
|
Excessive brake pedal effort
|
| • | Restricted air passage in power head |
| • | Improperly assembled brake booster valving |
| • | Incorrect lining material |
| • | Linings damaged by abusive use |
| • | Incorrect wheel cylinder sizes |
| • | Restricted brake fluid passage or sticking wheel cylinder piston |
| • | Brake pedal linkage interference or binding |
| • | Operator riding brake pedal |
| • | Sticking wheel cylinder or caliper pistons |
| • | Faulty proportioning valve |
|
Excessive braking action
|
| • | Contaminated brake lining |
| • | Linings damaged by abusive use |
| • | Leaking wheel cylinder or piston seal |
| • | Improperly assembled brake booster valving |
| • | Incorrect lining material |
| • | Heat spotted or scored brake drums or rotors |
| • | Incorrect wheel cylinder sizes |
| • | Weak or incorrect brake shoe retention springs |
| • | Incorrect stoplamp switch adjustment |
| • | Operator riding brake pedal |
| • | Improper booster pushrod length |
| • | Caliper not sliding freely |
| • | Faulty proportioning valve |
|
Brakes slow to respond
|
| • | Restricted air passage in power head |
| • | Contaminated or improper brake fluid |
| • | Improperly assembled brake booster valving |
| • | Brake pedal linkage interferenceor binding |
| • | Brake linkage interface or binding |
| • | Faulty proportioning valve |
|
Brakes slow to release
|
| • | Brake pedal linkage interference or binding |
| • | Contaminated or improper brake fluid |
| • | Restricted air passage in power head |
| • | Improperly assembled brake booster valving |
| • | Weak or incorrect brake shoe retention springs |
| • | Insufficient brake shoe guide lubricant |
| • | Restricted brake fluid passage or sticking wheel cylinder piston |
| • | Improper booster pushrod length |
| • | Sticking wheel cylinder or caliper pistons |
| • | Faulty proportioning valve |
|
Brakes drag
|
| • | Improperly assembled brake booster valving |
| • | Weak or incorrect brake shoe retention springs |
| • | Incorrect stoplamp switch adjustment |
| • | Brake pedal linkage interference or binding |
| • | Improper booster pushrod length |
| • | Faulty proportioning valve |
| • | Caliper not sliding freely |
| • | Sticking wheel cylinder or caliper pistons |
| • | Operator riding brake pedal |
| • | Parking brake cable seized |
| • | Improperly adjusted parking brake |
| • | Restricted brake fluid passage or sticking wheel cylinder piston |
| • | Insufficient brake shoe guide lubricant |
| • | Missing or loose brake assembly attachments |
| • | Faulty automatic adjusters |
| • | Contaminated or improper brake fluid |
|
Uneven braking action (side to side)
|
| • | Contaminated brake lining |
| • | Incorrect front end alignment |
| • | Leaking brake line or connection |
| • | Leaking wheel cylinder or piston seal |
| • | Uneven brake lining wear |
| • | Incorrect lining material |
| • | Linings damaged by abusive use |
| • | Heat spotted or scored brake drums or rotors |
| • | Faulty automatic adjusters |
| • | Incorrect wheel cylinder sizes |
| • | Weak or incorrect brake shoe retention springs |
| • | Missing or loose brake assembly attachments |
| • | Insufficient brake shoe guide lubricant |
| • | Restricted brake fluid passage or sticking wheel cylinder piston |
| • | Loose front suspension attachments |
| • | Sticking wheel cylinder or caliper pistons |
| • | Faulty proportioning valve |
|
Uneven braking action (front to back)
|
| • | Uneven brake lining wear |
| • | Incorrect lining material |
| • | Contaminated brake lining |
| • | Linings damaged by abusive use |
| • | Heat spotted or scored brake drums or rotors |
| • | Faulty automatic adjusters |
| • | Incorrect wheel cylinder sizes |
| • | Weak or incorrect brake shoe retention springs |
| • | Missing or loose brake assembly attachments |
| • | Insufficient brake shoe guide lubricant |
| • | Restricted brake fluid passage or sticking wheel cylinder piston |
| • | Parking brake cable seized |
| • | Operator riding brake pedal |
| • | Sticking wheel cylinder or caliper pistons |
| • | Faulty proportioner valve |
|
Scraping noise from brakes
|
| • | Loose front suspension attachments |
| • | Drums tapered or threaded |
| • | Insufficient brake shoe guide lubricant |
| • | Weak or incorrect brake shoe retention springs |
| • | Caliper not sliding freely |
| • | Incorrect wheel bearing runout |
| • | Loose or missing brake assembly attachments |
| • | Linings damaged by abusive use |
| • | Contaminated brake lining |
| • | Uneven brake lining wear |
|
Brakes squeak during application
|
| • | Insufficient brake shoe guide lubricant |
| • | Weak or incorrect brake shoe retention springs |
| • | Excessive lateral runout |
| • | Heat spotted or scored brake drum or rotors |
| • | Linings damaged by abusive use |
| • | Contaminated brake lining |
| • | Uneven brake lining wear |
|
Brakes squeak during application
|
| • | Weak or incorrect brake shoe retention springs |
| • | Operator riding brake pedal |
| • | Loose or missing brake assembly attachments |
| • | Heat spotted or scored brake drums or rotors |
| • | Linings damaged by abusive use |
| • | Contaminated brake lining |
| • | Incorrect lining material |
| • | Uneven brake lining wear |
|
Brakes pulsate (roughness)
|
| • | Caliper not sliding freely |
| • | Drums tapered or threaded |
| • | Improper rotor thickness variation |
| • | Incorrect lining material |
| • | Heat spotted or scored brake drums or rotors |
| • | Out-of-round brake drums |
| • | Excessive lateral runout |
| • | Missing or loose brake assembly attachments |
|
Brakes groan at end of stop
|
| • | Uneven brake lining wear |
| • | Incorrect lining material |
| • | Contaminated brake lining |
| • | Linings damaged by abusive use |
| • | Heat spotted or scored drums and rotors |
| • | Missing or loose brake assembly attachments |
| • | Loose front suspension attachments |
| • | Operator riding brake pedal |
|
BRAKE warning lamp glows
|
| • | Leaking brake line or connection |
| • | Leaking wheel cylinder or piston seal |
| • | Leaking master cylinder |
| • | Contaminated or improper brake fluid |
| • | Improperly adjusted parking brake |
| • | Parking brake cable seized |
|
