Trouble Shooter
|
FAULT | CAUSE | CURE |
Excessive brake pedal travel | 1. Brakes need adjusting or replacement. | 1. Adjust or renew brake shoes. |
| 2. Air in system. | 2. Bleed hydraulic system. |
| 3. Leaking or contaminated fluid. | 2. Bleed hydraulic system. |
| 4. Faulty master cylinder. | 4. Fit new master cylinder. |
Brake fade | 1. Incorrect pad or lining material. | 1. Fit new pads or shoes. |
| 2. Old or contaminated fluid. | 2. Renew brake fluid. |
| 3. Excessive use of brakes or car overloaded. | 3. Check vehicle load. |
Spongy brake pedal | 1. Air in hydraulic system. | 1. Bleed system. |
| 2. Shoes badly lined or distorted. | 2. Fit new pads or shoes. |
| 3. Faulty hydraulic cylinder. | 3. Check hydraulic circuit. |
Brake pedal too hard | 1. Seized wheel cylinder or calliper piston. | 1. Replace seized component. |
| 2. Glazed friction material. | 2. Fit new shoes/pads. |
Brake pedal requires pumping or loss of pedal | 1. Brakes wrongly adjusted. | 1. Adjust brakes. |
| 2. Air in hydraulic system. | 2. Bleed system. |
| 3. Fluid leak from component or brake pipe. | 3. Check hydraulic circuit and replace parts as necessary. |
| 4. Loss of fluid from master cylinder. | 4. Check hydraulic circuit and replace parts as necessary. |
Brakes grab when applied | 1. Contaminated friction material. | 1. Replace (don't clean) pads or shoes. |
| 2. Wrong linings fitted. | 2. Replace (don't clean) pads or shoes. |
| 3. Scored drums or discs. | 3. Fit new drum or disc. |
Brake squeal | 1. Worn retaining pins (disc). | 1. Fit new pins. |
| 2. Faulty damping shims or shoe retaining clips. | 2. Fit new shims or clips. |
| 3. Dust in drum. | 3. Remove dust from drums and shoe. |
| 4. Loose backplate or calliper. | 4. Tighten calliper or backplate. |
Brake judder | 1. No clearance at master cylinder operating rod. | 1. Adjust rod if possible. |
| 2. Shoe tension springs either broken or weak. | 2. Replace tension springs. |
| 3. Wheel cylinder or calliper piston seizing. | 3. Fit new calliper or cylinder. |
| 4. Faulty self-adjusting mechanism. | 4. Check mechanism. |
| 5. Seized handbrake mechanism. | 5. Check handbrake operation. |
Brake pull to one side | 1. Contaminated friction material on one side only (grease, oil or brake fluid). | 1. Replace shoes/pads all round. |
| 2. Loose backplate. | Tighten backplate. |
| 3. Seized cylinder. | Replace seized cylinder. |
| 4. Faulty suspension or steering. | 4. Check suspension and steering. |
Handbrake ineffective | 1. Worn rear shoes or pads. | 1. Fit new pads/shoes. |
| 2. Brakes require adjusting. | 2. Adjust brakes. |
| 3. Faulty handbrake linkage. | 3. Check linkage and operating mechanism. |
| 4. Cable or rod requires adjustment. | 4. Adjust cable or rod. |
Servo (where fitted) late in operation | 1. Blocked filter. | 1. Clean or replace filter. |
| 2. Bad vacuum sealing or restricted air inlet. | 2.Tighten vacuum hose connections and check hoses. |
Loss of servo action when braking heavily | 1. Air leak in servo - vacuum low. | 1. Either overhaul servo or replace. |
Loss of fluid (Servo only) | 1. Seal failure. | 1. Replace or overhaul servo. |
| 2. Scored servo bores. | 2. Replace or overhaul servo. |
| 3. Damaged or corroded fluid pipes. | 3. Inspect and fit new pipes. |