What are the symptoms of a bad brake master cylinder?
3 Answers
The manifestations of a faulty brake master cylinder are as follows: 1. Component failure: Oil leakage occurs at the connection between the brake master cylinder and the vacuum booster or at the limit screw, poor or ineffective braking after fully depressing the brake pedal, and a soft feeling when pressing the brake pedal. 2. Brake failure: The vehicle pulls to one side after braking, sudden brake failure, the brake pedal not returning or returning slowly. Relevant information is as follows: 1. Definition: The brake master cylinder, also known as the "brake main cylinder" or "brake master cylinder", is the main coordinating component of the vehicle's braking system. 2. Classification: Depending on the vehicle, it is divided into two types: air brake master cylinders and hydraulic brake master cylinders. Generally, passenger cars mostly use hydraulic brake master cylinders, while commercial vehicles (such as trucks, buses, tractors, etc.) usually use air brake master cylinders.
My car once had a brake master cylinder failure, and during that time, the brake pedal felt noticeably soft, like stepping on cotton. Once, a pedestrian suddenly rushed out at an intersection, and when I pressed the brake hard, I found the pedal almost hitting the floor before the car slowly came to a stop, sending chills down my spine. Later, I noticed the brake fluid reservoir was always low, and there were small oil stains on the ground. After inspection, I realized the master cylinder's sealing ring was leaking. The worst part was during cold starts, when I had to pump the brakes two or three times before they returned to normal travel. Thinking about it now still gives me chills. I recommend everyone pay attention to signs like a soft or deep brake pedal, especially checking for abnormal drops in fluid levels—it's crucial for driving safety.
Last week, my neighbor Lao Zhang's car almost had an accident due to a faulty brake pump. He mentioned that when continuously applying the brakes, he could feel the vehicle pulling to one side—the right wheel stopped while the left one kept rolling. The round brake warning light on the dashboard also lit up yellow, resembling a small sun. The mechanic told him this was a classic case of uneven brake force distribution, where a failure in pressure transmission caused abnormal braking on one side. After researching, I learned that brake pumps are divided into master cylinders and wheel cylinders. A failure in the master cylinder leads to overall weak braking, while a faulty wheel cylinder results in the kind of one-sided failure Lao Zhang experienced. If you encounter a similar situation, you must stop and check immediately—don’t push through like he did, driving all the way to the highway exit before heading to the repair shop.
