What Could Be Causing Brake Abnormalities?

During driving, the brake system acts as the car's “safety guardian,” ensuring our driving safety. However, when brakes malfunction, it's like the safety guardian has fallen ill, causing great concern. So, what could be causing brake abnormalities? Let's take a detailed look below.

1. Causes of brake abnormalities

1) Excessive brake pad wear

Brake pads  are the key components in the braking system that generate friction to slow the vehicle. As usage time increases and mileage accumulates, brake pads gradually wear down. When brake pads wear down to a certain extent, their thickness decreases, reducing friction and leading to poor braking performance, such as increased braking distance or soft braking. Generally, when the thickness of the brake pads is less than one-third of the original thickness, they should be replaced promptly. Additionally, if a sharp metallic grinding sound is heard during braking, this is likely caused by the wear indicator on the brake pad rubbing against the brake rotor. In such cases, the brake pads must be replaced immediately to prevent further damage to the brake rotor.

2) Brake Rotor Issues

Brake rotors work in tandem with brake pads to complete the braking process. Common issues with brake rotors include wear, deformation, and cracks. Prolonged use and frequent braking can cause wear on the surface of the brake rotor, forming grooves. When the brake rotor is severely worn, it affects the contact between the brake pads and the rotor, leading to uneven braking force and causing the vehicle to shake during braking. Brake discs may also deform under high temperatures and frequent braking. Deformed brake discs can cause the brake pedal to vibrate during rotation, significantly affecting driving experience and road safety. Additionally, cracks in the brake disc are a serious issue. Cracks reduce the disc's strength and may cause it to fracture during braking, potentially leading to severe accidents. Therefore, it is crucial to regularly inspect the condition of the brake discs and replace them promptly if any issues are detected.

3) Brake fluid issues

Brake fluid plays a role in transmitting pressure within the braking system. If there are issues with the brake fluid, it will directly affect the normal operation of the braking system. Brake fluid is hygroscopic, meaning it absorbs moisture from the air over time, which lowers its boiling point. In high-temperature environments or during frequent braking, the moisture in the brake fluid can boil and form bubbles. These bubbles are compressible, causing the brake pedal to feel soft and resulting in reduced braking power. Additionally, if brake fluid is not replaced for an extended period, it can degrade and produce impurities. These impurities may clog the brake lines, obstructing the normal flow of brake fluid and causing brake failure. Therefore, it is essential to replace brake fluid regularly in accordance with the vehicle manual's specifications. It is generally recommended to replace brake fluid every two years or after driving 40,000 to 60,000 kilometers.  

4) Brake caliper malfunction

The brake caliper is the component that pushes the brake pads into contact with the brake rotor. Brake calipers may experience issues such as oil leaks or piston sticking. If a brake caliper leaks oil, it can cause a decrease in brake fluid levels, resulting in insufficient brake pressure and reduced braking effectiveness. When the brake caliper piston is stuck, the brake pads cannot separate from or properly engage with the brake rotor, resulting in brake drag or uneven braking force. If brake caliper fluid leakage or other abnormalities are detected, timely repairs or replacements should be performed.

5) Brake line issues

Brake lines are responsible for conveying brake fluid. If brake lines develop cracks, blockages, or aging issues, it can affect the normal flow of brake fluid and pressure transmission. A cracked brake line can cause brake fluid leakage, resulting in loss of brake system pressure and brake failure. Blockages in the lines can prevent brake fluid from flowing smoothly, causing the brake calipers to malfunction and reducing braking effectiveness. Aging brake lines can weaken their structural integrity, making them prone to ruptures and leaks. Therefore, regularly inspecting the condition of the brake lines and promptly repairing or replacing them when issues are detected can effectively prevent abnormal braking conditions.

6) Other possible causes

In addition to the common causes mentioned above, brake malfunctions may also be related to other factors. For example, sensor failures in the brake system may cause the brake warning light to illuminate or result in incorrect brake system operation. Insufficient tire pressure or severe tire wear can also affect braking performance, as reduced friction between the tires and the road surface can increase braking distance. Additionally, suspension system failures may cause the vehicle to become unstable during braking, affecting braking smoothness.

2.Brake System Self-Inspection Manual

1) Visual Inspection Method

Observe the brake fluid reservoir level (should be between MAX and MIN)

heck the brake pad thickness (must be replaced if <3mm)

Check the brake disc groove depth (must be polished if >1.5mm)

2) Auditory Diagnostic Method

A “squeaking” sound when lightly applying the brakes: normal friction sound

A continuous sharp screeching sound: brake pad warning or improper installation

A metallic clanging sound: brake pads are completely worn out

3) Tactile Test Method

When the engine is cold, press the brake pedal: the pedal travel should be <1/3 of the total travel

During braking, the steering wheel should not deviate by more than 5°

4) Tool-assisted method

Use an infrared thermometer: the brake disc temperature after braking should be <450°C

Brake fluid moisture content tester: >3% requires replacement

3. Emergency situation handling guidelines

1) Complete brake failure

• Stay calm and activate hazard lights

• Continuously engage and release the handbrake (for electronic handbrakes, hold down to activate emergency braking)

• Downshift to reduce speed (switch to manual mode for automatic transmissions)

• Friction braking (use guardrails/sand piles)

2) Brake Fluid Leakage

• Immediately stop the vehicle and turn off the engine

• Wrap the leakage point with a towel (do not touch directly with your hands)

• Call for a tow truck; do not continue driving

3) ABS malfunction

• Turn off the ABS switch (if available)

• Use the “pulse braking” method (2-3 times per second)

• Maintain straight-line driving and avoid sharp turns

When encountering brake abnormalities, remain calm, safely pull over to the side of the road, and contact professional maintenance personnel as soon as possible for inspection and repair. Regular maintenance and inspection of the braking system can help identify potential issues promptly, ensuring the braking parts remains in optimal working condition to safeguard your driving safety. If you have any further questions of brake pads, brake discs and other brake parts or require additional assistance regarding the braking system, please feel free to contact us at any time. We will provide you with professional advice and services. Our phone number is +86-13363216781.Our website is https://www.evfriction.com.