Illustrate common noise and faults of brake pads

Noise type

High frequency scream

The high-frequency sound sounds sharp, and when the vibration frequency of the brake disc and the brake pad are the same, they resonate to produce a scream.
Check the caliper: whether the guide rail is lubricated smoothly and whether the piston oil seal is damaged.
Check whether all anti-noise clips and brake pads are suitable and installed correctly.
Check whether the brake pads are too smooth and are not overused.

Low frequency howl

Commonly called caliper noise
Caused by the vibration of the caliper assembly
It may also be caused by the vibration of the suspension system
The new car's caliper or suspension system has a slight vibration
Early morning sensitivity, such as early morning in winter, is especially common
Check the calipers, suspension system and bushings

Dull echo

Generally produced when the pedal is slack
Easy to cause the steering wheel to shake
New models are prone to such problems
Caused by the difference in the thickness of the brake disc
Maintenance of the ball cage connector
Check the degree of wear of the brake pads

Abnormal after the moving disc is worn

reason

Dirty brake disc surface
Uneven brake disc material density
Excessive working temperature
Brake disc installation torque does not match

an examination

The brake disc must be checked before replacing the brake pads
Check the thickness of the brake disc with a caliper
Reinstall the bolts of the fixed brake disc
Measuring the flatness of the working surface of the brake disc

Case one

Appearance: The friction material is locally bright
Reason: Pistons work on different axes; the density of brake pad friction material is uneven.
Impact: The brake pads wear quickly, and the brake disc is partially worn.
Measures: Adjust the piston, check the seals, and replace the brake pads.

Case 2

Appearance: The friction material is oily
Reason: sticky oil during repair or maintenance
Influence: unbalanced coaxial braking force, braking deviation
Measures: Replace the brake pads

Case Three

Appearance: The edges of the friction material are worn into arcs or grooves.
Reason: The brake disc is severely worn and caused by human factors.
Impact: car jitter, abnormal noise, abnormal wear of brake pads.
Measures: Use obsolete brake pads to polish the edge of the brake disc to no grooves to prevent artificial chamfering, and replace the brake disc if necessary
Case Four

Appearance: Part of the brake pads are worn
Reason: There is an inclusion between the brake disc and the brake pad
Effect: noise during braking, damage to the brake disc
Measures: Replace the brake discs and brake pads in severe cases

Case 5

Appearance: foreign matter in the friction material
Reason: not preventable
Impact: abnormal noise of the car, damage to the brake disc
Measures: Replace the brake pads, the groove of the brake disc obviously needs to be replaced