What are the common faults of brakes?

The cause of brake failure: 1. The brake pedal stroke of the car is too large; 2. Insufficient or no oil in the reservoir chamber of the brake master cylinder; 3. The brake fluid of the car has deteriorated

5 common faults of the braking system:

First, poor braking efficiency phenomenon: When the car brakes, the braking deceleration is small and the braking distance is long.

Reason:

1. The master cylinder is faulty.

2. There is a problem with the auxiliary cylinder

3. The brake is faulty

4. Air seeps into the brake pipe

Diagnosis: The reasons for the poor braking efficiency of hydraulic braking systems can generally be determined based on the brake pedal stroke (commonly known as high or low), the softness and hardness when pressing the brake pedal, the stability after pressing the brake pedal, and the increase in pedal height when braking multiple times in border areas

1. Generally, the pedal height is too low and the braking efficiency is poor. If two or more feet brake continuously, the pedal height increases and the braking efficiency improves, indicating that the gap between the brake drum and the friction plate or between the master cylinder piston and the push rod is too large

When holding the brake, if the pedal height drops slowly or the speed is appropriate, it indicates that there is a broken part in the brake pipeline, poor joint sealing or poor sealing of the auxiliary cylinder cup, too soft or broken return spring, or poor sealing of the main cylinder cup and cup, as well as poor sealing of the return valve and outlet valve. Firstly, press the brake pedal and observe for any brake fluid leaks. If the appearance is normal, check for faults in the auxiliary cylinder or master cylinder

3. Brake continuously several times, but the pedal height is still too low. After a good foot brake, it feels like the master cylinder piston has not returned to its original position. When stepping on the brake pedal, there will be a knocking sound between the master cylinder push rod and the piston, which is caused by the master cylinder cup breaking or several consecutive times, and the return spring being too soft

4. When braking continuously for a few steps, the pedal height slightly increases and there is a sense of elasticity, indicating that air has infiltrated the brake pipeline

5. After several consecutive steps, if the pedal is pressed to the bottom and there is no reaction force on the pedal, it indicates that the brake fluid in the master cylinder reservoir is severely lost

6. When braking continuously for a few feet, the pedal height is low and soft, which is caused by the blockage of the ventilation hole in the storage chamber plug in the main oil inlet hole

7. When braking with one or both feet, the pedal height is appropriate, but it is too difficult to brake effectively. Check if the gap between the friction parts of each wheel and the drum is too small, and if the medium and high speeds are improper. If the gap is normal, check the surface condition of the drum wall and friction plate. If normal, check if the brake shoe spring is too hard, if the master cylinder or slave cylinder cup is expanding, and if the piston is loose in fitting with the cylinder wall. If everything is normal, check if the brake hose is aging

Secondly, the phenomenon of sudden brake failure: When a car is driving, one or several feet brake continuously, and the brake pedal is pressed all the way, causing the brake to suddenly fail

Reason:

1. There is no brake fluid in the master cylinder.

2. The master cylinder cup is damaged or overturned

3. The dispenser cup is damaged or overturned

4. The brake pipe is severely broken or the joint is disconnected

Diagnosis: If the brake fails, stop immediately for inspection. Firstly, observe if the brake fluid is leaking. Brake fluid at the dust cover of the master cylinder push rod. If there is a severe brake fluid leakage at the dust cover of the master cylinder push rod, it is likely caused by the master cylinder cup being stepped on or severely damaged. If there is a large amount of brake fluid at the edge of the wheel brake drum, it means that the wheel cylinder cup is overturned or severely damaged. The leakage of brake fluid in the pipeline is generally very obvious. If there is no brake fluid leakage, check if the brake fluid in the master cylinder reservoir is sufficient

Thirdly, brake bite phenomenon: When pressing the brake pedal, it feels high and hard or there is no free travel, making automatic starting difficult or driving difficult

Reason:

1. The brake pedal does not have free travel or its return spring falls off, breaks, or is too soft.