General Diagnostics: Inspection
PROBLEM SYMPTOM DIAGNOSTICS
| Trouble and possible cause | Corrective action | |
|---|---|---|
| 1. Insufficient braking | (a) Fluid leakage from the hydraulic mechanism | Repair or replace (cup, piston seal, piston boot, master cylinder piston kit, pipe or hose). |
| (b) Entry of air into the hydraulic mechanism | Bleed the air. | |
| (c) Excessively wide shoe clearance | Adjust the clearance. | |
| (d) Wear, deteriorated surface material, adhering water or fluid on the lining | Replace, grind or clean. | |
| (e) Improper operation of master cylinder, disc caliper, brake booster or check valve | Correct or replace. | |
| 2. Unstable or uneven braking | (a) Fluid on the lining or rotor | Eliminate cause of fluid leakage, clean, or replace. |
| (b) Rotor eccentricity | Correct or replace the rotor. | |
| (c) Improper lining contact, deteriorated surface material, improper inferior material, or wear | Correct by grinding, or replace. | |
| (d) Deformed back plate | Correct or replace. | |
| (e) Improper tire inflation | Inflate to correct pressure. | |
| (f) Disordered wheel alignment | Adjust alignment. | |
| (g) Loosened back plate or the support installing bolts | Retighten. | |
| (h) Loosened wheel bearing | Retighten to normal tightening torque or replace. | |
| (i) Trouble in the hydraulic system | Replace the cylinder, brake pipe or hose. | |
| (j) Uneven effect of the parking brake | Check, adjust, or replace the rear brake and cable system. | |
| 3. Excessive pedal stroke | (a) Entry of air into the hydraulic mechanism | Bleed the air. |
| (b) Excessive play in the master cylinder push rod | Adjust. | |
| (c) Fluid leakage from the hydraulic mechanism | Repair or replace (cup, piston seal, piston boot, master cylinder piston kit, pipe or hose). | |
| (d) Improperly adjusted shoe clearance | Adjust. | |
| (e) Improper lining contact or worn lining | Correct or replace. | |
| 4. Brake dragging or improper brake return | (a) Insufficient pedal play | Adjust play. |
| (b) Improper master cylinder return | Clean or replace the cylinder. | |
| (c) Clogged hydraulic system | Replace. | |
| (d) Improper return or adjustment of parking brake | Correct or adjust. | |
| (e) Weakened spring tension or breakage of shoe return spring | Replace the spring. | |
| (f) Excessively narrow shoe clearance | Adjust the clearance. | |
| (g) Improper disc caliper operation | Correct or replace. | |
| (h) Improper adjusted wheel bearing | Adjust or replace. | |
| 5. Brake noise (1) (creak sound) | (a) Hardened or deteriorated lining | Replace the shoe assembly or pad. |
| (b) Worn lining | Replace the shoe assembly or pad. | |
| (c) Loosened back plate or the support installing bolts | Retighten. | |
| (d) Loose wheel bearing | Retighten to normal tightening torque. | |
| (e) Dirty rotor | Clean the rotor, or clean and replace the brake assembly. | |
| 6. Brake noise (2) (hissing sound) | (a) Worn lining | Replace the shoe assembly or pad. |
| (b) Improper installed shoe or pad | Correct or replace the shoe assembly or pad. | |
| (c) Loose or bent rotor | Retighten or replace. | |
| 7. Brake noise (3) (click sound) | (a) Excessively worn pad or the support | Replace the pad or the support. |
| (b) Excessively worn shoe ridge | Replace the back plate. | |
| (c) Lack of oil on the shoe ridge surface and anchor | Add more grease. |