+86-13363216781
Views: 29 Author: Site Editor Publish Time: 2025-12-24 Origin: Site
Brake pads, as the primary wearer of the braking system, should normally wear at a roughly uniform rate on both sides (with a deviation of no more than 1-2mm). However, in real-world use, many owners experience uneven wear, with one side thinning and the other remaining intact. This not only shortens the life of the pads but can also cause brake slip and steering wheel tremors, posing safety hazards. This article systematically analyzes the core causes of uneven brake pad wear and provides targeted troubleshooting methods and solutions to help owners mitigate these risks.
The brake caliper (brake caliper) is the core component that pushes the brake pads against the brake disc. Problems such as piston sticking and seal aging can directly lead to uneven force distribution on both sides of the brake pads and are the most common cause of uneven wear, accounting for over 60% of all wear.
The wheel cylinder pushes the brake padby extending and retracting the piston. If the piston becomes stuck in the "extended" position due to impurity accumulation or insufficient lubrication, the brake pad on the opposite side will remain in contact with the brake disc for a long time, resulting in "drag wear." If the piston becomes stuck in the "retracted" position, the brake pad will not fully adhere to the brake disc, wearing more slowly and ultimately causing differential wear on both sides.
Long-term failure to replace the brake fluid (over 2 years or 40,000 kilometers) can lead to oxidation impurities inside the fluid, which can clog the piston seal.
Aging of the wheel cylinder piston seal (rubber material has a lifespan of approximately 3-5 years), reducing sealing performance and allowing impurities to penetrate the piston cavity.
Long-term operation in muddy and dusty conditions can damage the wheel cylinder dust boot, allowing mud and sand to enter the piston.
The brake pads on some models are secured by "guide pins" on the wheel cylinder bracket. If these pins become stuck due to rust or lack of oil, the brake pads will not slide along their normal path, causing "misalignment" when contacting the brake disc. This can lead to excessive friction pressure in certain areas, resulting in "partial wear" (e.g., faster wear at the edges of the pad and slower wear in the center).
Coastal areas or roads covered in salt in winter, where salt corrodes the metal surface of the guide pins, forming a rust layer;
Failure to apply special grease to the guide pins during maintenance (use high-temperature resistant brake grease, not ordinary butter), resulting in dry wear.
Detailed errors in the brake pad installation process can directly lead to an abnormal initial position. This is a "human factor" that causes uneven wear and accounts for approximately 10% of all wear. Common problems are mainly due to gaps, incorrect orientation, and missing parts.
A reasonable clearance (typically 0.1-0.2mm) should be maintained between the brake pad and the wheel cylinder bracket. Failure to adjust this clearance during installation, or if the brake pad size and bracket do not match (e.g., using a "universal" brake pad instead of a specialized model), will prevent the brake pad from sliding freely and result in only partial contact with the brake disc.
Some brake pads are designed with a "friction direction indicator" (such as an arrow indicating the direction of wheel rotation). If installed the wrong way around, the friction material of the pad will contact the brake disc at an abnormal angle, concentrating friction pressure on one side while dispersing it on the other. For example, ceramic brake pads often have a "guide groove" design on the friction material. Installing the pad the wrong way around prevents friction dust from being removed, leading to excessive accumulation of dust and slower wear.
Missing "silencer" or "cushion" pad: Some brake pads come with a metal silencer or rubber cushioning pad on the back. If this pad is omitted during installation, it can cause "vibration deviation" when the pad is applied to the brake disc, accelerating localized wear.
Missing guide pin dust boot: A missing dust boot can quickly allow mud and sand to enter the guide pin, accelerating sticking and indirectly causing uneven wear.
In addition to hardware failures, poor driving habits and unusual vehicle usage environments can also exacerbate uneven brake pad wear. These factors are considered "acquired factors," accounting for approximately 2%. While the impact is relatively minor, they can accumulate over time and lead to significant deviations.
Some drivers habitually apply pressure on one side when braking (e.g., holding the steering wheel with their right hand and lightly applying the brake with their left foot, resulting in uneven pressure on the brake pedal and indirectly affecting the wheel cylinder's thrust);
If the vehicle is slightly swerving (and not corrected in time), the driver may unconsciously apply unilateral braking (lightly applying more force to one side) to maintain a straight line. This can lead to accelerated brake pad wear on the corresponding side over time.
If a vehicle is frequently driven on unilaterally inclined roads (such as winding mountain roads or sections of road under construction on one side), gravity will cause the wheel to shift toward the lower side. The brake disc tilts slightly with the wheel, increasing the contact pressure on the lower side of the brake pad and causing it to wear faster than the upper side.
If uneven brake pad wear is discovered, troubleshoot according to the principle of "simple to complex, easy first, difficult later":
Preliminary Inspection: Remove the wheel and observe the thickness difference between the two sides of the brake pad and record it; check the surface flatness of the brake disc and the looseness of the wheel hub bearing.
Core Inspection: Focus on checking whether the brake wheel cylinder piston extends and retracts smoothly and whether the guide pin is rusted or lacking oil (this can be tested by applying special grease). If the wheel cylinder is stuck, clean or replace it. Perform a four-wheel alignment to check the suspension angle. If it exceeds the standard, adjust or replace the component. Also, check and replace any abnormal wheel hub bearing.
Repair and Replacement: If the wheel cylinder guide pin is stuck, clean and lubricate it without replacing the wheel cylinder. If the wear difference is less than 2mm and the brake disc is in good condition, only the brake pads can be replaced. If the wear difference exceeds 3mm or reaches the limit, replace both brake pads. Minor uneven wear of the brake disc can be repaired by "smoothing", while severe wear requires replacement.
Wear-resistant and stable brake pads are crucial to driving safety and also affect the driving experience.Scientific inspection and maintenance can address wear issues, extend the life of the brake system, and ensure driving safety. Choosing safe and reliable brake parts is also crucial.If you are looking for high-quality brake pads to replace,welcome to visit our website:https://www.evfriction.com .Please contact us by +86-13363216781 or jessicabrakes12@gmail.com if you have questions.
