The brake pedal travel is too large, the braking effect is slow, the braking efficiency is very low or even lost, and the braking distance increases.
Cause of failure:
1. Insufficient brake oil pressure. (The brake master cylinder lacks oil, the brake pipe is broken, the oil pipe joint is leaking, and the oil circuit is blocked).
2. There is air in the braking system.
3. The free travel of the brake pedal or the brake clearance is too large, the brake shoe friction pads are in poor contact, the wear is serious or there is oil pollution.
4. The brake master cylinder, wheel cylinder piston and cylinder tube are worn or strained, and the leather cup is aged and damaged.
Troubleshooting
1. Depress the brake pedal continuously, for example, the pedal is gradually raised and has a springy feeling, but stop for a while before depressing it When the plate is still low, there is air in the braking system, and the braking system should be exhausted at this time.
2. The braking with one foot does not work, but the braking effect is very good when the pedal is stepped on several times in a row. Generally, the free travel of the brake pedal is too large or the braking gap is too large. The pedal free travel should be adjusted, and then the brake clearance should be checked, and if necessary, the brake should be disassembled and repaired.
3. When the brake pedal is stepped on, it is neither weak nor heavy, but the braking effect is not good. This phenomenon is a wheel brake failure, such as oil or poor contact of the brake shoes, and aging of the friction pads. , wear, uneven wear of the brake drum. The technical condition of the brakes should be checked, adjusted and repaired if necessary.