How does the wear of drum brake linings relate to brake performance?

There is a close relationship between the wear of drum brake linings and the braking performance. As the linings are used for a longer time, the friction material gradually wears away, which can lead to a gradual decrease in braking performance. The following is a detailed description of the relationship between wear and braking performance:

Reduction in Friction Coefficient
The friction of drum brake linings is a key factor in determining braking performance. The friction coefficient between the lining surface and the brake drum directly affects the deceleration effect when braking. When the brake linings are worn, the friction surface changes, resulting in a gradual decrease in the friction coefficient. This means that the linings produce less resistance when braking, resulting in longer braking distances and reduced braking effect.

Thermal Fading Effect
When braking, the friction between the lining and the brake drum generates a lot of heat, and the heat resistance of the lining directly affects its braking effect. During the wear of the lining, its surface structure may be affected by high temperatures, resulting in a decrease in the thermal stability of the lining material. As the lining wears, thermal fading may occur, that is, the friction coefficient of the lining decreases significantly at high temperatures. This situation will cause the braking performance to further decrease during long-term or high-load braking, increasing the risk of brake failure.

Reduced brake pad thickness
Pad thickness is an important factor in determining its service life and friction area. As the pad wears, the thickness gradually decreases, and the friction surface area decreases. Thinner pads mean less surface area in contact with the brake drum each time the brake is applied, which can lead to less stable friction and poorer braking results. Insufficient pad thickness can also lead to uneven contact between the pad and the drum, which further affects braking performance and may even cause problems such as noise and vibration.

Changes in the uniformity of friction materials
As the pad is used, the uniformity of the friction material may change. For example, there may be excessive wear in some areas, while more friction material may remain in other areas. This uneven wear can lead to uneven distribution of friction during braking, and may cause instability during braking, such as fluctuations in braking force and vibration, which can affect braking effect and comfort.

Changes in the surface of the brake pad
As the pad wears, its surface structure also changes. Initially, the pad surface is relatively smooth and the friction coefficient is stable; but as it is used, the surface becomes rough or cracked, which not only causes a change in the friction coefficient, but may also increase further wear of the pad. This irregular surface affects the distribution of heat during braking, which may cause local overheating of the pads, further affecting braking performance.

Uneven distribution of braking force
When the pads wear unevenly, the braking force in different areas will be unevenly distributed, which will lead to unstable braking system effect. For example, some areas may have insufficient braking force due to severe wear and cannot effectively slow down; while other areas may have excessive braking force due to new pads, resulting in unbalanced braking force distribution, unstable braking effect, and even causing loss of control of the braking system.

Noise and vibration of the brake system
Pad wear can also cause noise and vibration in the brake system. As the pads wear, the contact surface between the pads and the brake drum may become uneven, resulting in sudden or uneven friction during braking, resulting in brake noise. At the same time, uneven wear of the pads may cause fluctuations in braking force and vibration. These factors not only affect braking performance, but may also affect driving comfort and the long-term stability of the brake system.

Relationship between wear and safety
As the brake pads wear, their braking effect will gradually weaken, which may lead to longer braking distances and increase the risk of traffic accidents. Especially in the case of sudden braking or long braking, badly worn pads will significantly reduce the braking effect and increase the possibility of brake decay. Therefore, regular inspection and replacement of brake pads are important measures to ensure driving safety.

There is a direct relationship between the wear of drum brake pads and braking performance. Pad wear will lead to a decrease in friction coefficient, weakened braking effect and instability of the brake system. In order to maintain the good performance of the brake system, extend the service life and ensure driving safety, it is essential to regularly inspect, monitor and replace badly worn brake pads. At the same time, choosing the right materials and processes and avoiding improper driving habits can also help slow down the wear of the pads and keep the brake system running efficiently.