What are the common faults in automotive braking systems?
2 Answers
Common faults and diagnostic causes in automotive braking systems are as follows: 1. Fault symptom: Brake pedal does not rise and lacks resistance when pressed. Diagnostic cause: Check for brake fluid deficiency; inspect for oil leaks at brake wheel cylinders, pipelines, and joints; examine potential damage to master cylinder or wheel cylinder components. 2. Fault symptom: Pedal returns higher after repeated pumping with improved braking effect. Diagnostic cause: Excessive clearance between brake shoes and drum. 3. Fault symptom: Normal pedal height without softening or sinking, but poor braking performance. Diagnostic cause: Excessive clearance between brake shoes and drum or oil contamination. 4. Fault symptom: Slow recovery of brake fluid level. Diagnostic cause: Loosen bleeder screw to observe brake shoe return. If shoes return, unclog fluid lines; if not, disassemble and inspect wheel cylinders.
Last time my car's brake pedal felt unusually soft, and after checking for a long time, I found out it was due to low brake fluid and a leak. Actually, brake problems are quite common. I've figured out several types: if the brake pads wear down to the metal, they'll squeak; if they're worn to the limit, the car won't stop. If the brake discs are uneven or warped, the whole car will shake when braking. If the brake hose is broken or the connection is leaking, the pedal will go all the way down with no response. If air gets into the brake lines, the brakes will feel spongy. If the parking brake cable rusts and seizes, it won't hold the car on a slope. The scariest is when the brake master cylinder fails—I experienced this once, driving late at night when suddenly the pedal sank to the floor, and my scalp tingled. Now I tell people that regularly checking the brake pad thickness is the most important thing, and to fix any strange noises immediately, not like me who ended up sweating after the fact.
