Why does the brake pedal feel higher than before after replacing the car brake pads?
[Catalog:News] [Date:2025/1/10] [Hits:] [Return]
Air exhaust status of brake system
During the process of replacing brake pads, air may enter the brake system pipeline. If the air is not completely emptied, it will affect the normal transmission pressure of brake fluid. Air has compressibility, and when the brake pedal is pressed, a portion of the pressure transmitted by the brake fluid will be absorbed by the air, causing a delay in the response of the brake pads. In order to overcome the influence of air and ensure the normal operation of brake pads, car owners often need to press the brake pedal deeper, which makes the position of the brake pedal appear lower during normal braking.
However, if the air in the brake system is well drained and the brake fluid can smoothly transmit pressure after replacing the brake pads, the brake pads can quickly respond to the action of the brake pedal. Compared to when the air is not completely emptied, the brake pedal does not need to be pressed too deeply to achieve effective braking, and the position of the brake pedal is relatively higher. That's also why maintenance personnel carefully perform exhaust operations on the brake system after replacing the brake pads to ensure stable and reliable braking performance.
The condition of brake calipers and pistons
The brake caliper and piston play a crucial role in the braking process. During long-term use, brake calipers and pistons may experience some degree of wear, jamming, or other malfunctions. After replacing the brake pads, if the problem with the brake calipers or pistons is not properly addressed, it may affect the height of the brake pedal.
For example, after long-term use, the brake caliper piston may not move smoothly due to corrosion on the piston surface, aging of seals, and other reasons. After replacing the brake pads, the piston may not be able to push the brake pads into contact with the brake disc as quickly and accurately as normal. This requires the brake pedal to apply a greater stroke to overcome the resistance of the piston, allowing the brake pads to reach the appropriate braking position, resulting in a lower brake pedal feel.
On the contrary, if the brake calipers and pistons are inspected and maintained when replacing the brake pads to ensure that the pistons can move flexibly, then during braking, the pistons can quickly push the new brake pads into close contact with the brake disc, and the brake pedal can achieve effective braking at a relatively high position, giving the car owner the feeling of a higher brake pedal.
Adaptive and Running in of Braking System
The braking system of modern cars often has a certain adaptive function. After replacing the brake pads, the vehicle's electronic control system may take some time to adapt to the characteristics and working status of the new brake pads. During this adaptive process, the feeling of the brake pedal may change. As the vehicle travels, the brake system continuously adjusts and optimizes its control over the new brake pads, and the height of the brake pedal may gradually stabilize.
In addition, there needs to be a break in stage between the new brake pads and brake discs. In the early stage of running in, the contact area and friction force distribution between the two may not be uniform, which can also affect the performance of the brake and the feel of the brake pedal. As the running in process progresses, the brake pads and brake discs gradually adapt to each other, with tighter and more uniform contact. The braking performance will gradually improve, and the height of the brake pedal will also tend to be normal.
During the process of replacing brake pads, air may enter the brake system pipeline. If the air is not completely emptied, it will affect the normal transmission pressure of brake fluid. Air has compressibility, and when the brake pedal is pressed, a portion of the pressure transmitted by the brake fluid will be absorbed by the air, causing a delay in the response of the brake pads. In order to overcome the influence of air and ensure the normal operation of brake pads, car owners often need to press the brake pedal deeper, which makes the position of the brake pedal appear lower during normal braking.
However, if the air in the brake system is well drained and the brake fluid can smoothly transmit pressure after replacing the brake pads, the brake pads can quickly respond to the action of the brake pedal. Compared to when the air is not completely emptied, the brake pedal does not need to be pressed too deeply to achieve effective braking, and the position of the brake pedal is relatively higher. That's also why maintenance personnel carefully perform exhaust operations on the brake system after replacing the brake pads to ensure stable and reliable braking performance.
The condition of brake calipers and pistons
The brake caliper and piston play a crucial role in the braking process. During long-term use, brake calipers and pistons may experience some degree of wear, jamming, or other malfunctions. After replacing the brake pads, if the problem with the brake calipers or pistons is not properly addressed, it may affect the height of the brake pedal.
For example, after long-term use, the brake caliper piston may not move smoothly due to corrosion on the piston surface, aging of seals, and other reasons. After replacing the brake pads, the piston may not be able to push the brake pads into contact with the brake disc as quickly and accurately as normal. This requires the brake pedal to apply a greater stroke to overcome the resistance of the piston, allowing the brake pads to reach the appropriate braking position, resulting in a lower brake pedal feel.
On the contrary, if the brake calipers and pistons are inspected and maintained when replacing the brake pads to ensure that the pistons can move flexibly, then during braking, the pistons can quickly push the new brake pads into close contact with the brake disc, and the brake pedal can achieve effective braking at a relatively high position, giving the car owner the feeling of a higher brake pedal.
Adaptive and Running in of Braking System
The braking system of modern cars often has a certain adaptive function. After replacing the brake pads, the vehicle's electronic control system may take some time to adapt to the characteristics and working status of the new brake pads. During this adaptive process, the feeling of the brake pedal may change. As the vehicle travels, the brake system continuously adjusts and optimizes its control over the new brake pads, and the height of the brake pedal may gradually stabilize.
In addition, there needs to be a break in stage between the new brake pads and brake discs. In the early stage of running in, the contact area and friction force distribution between the two may not be uniform, which can also affect the performance of the brake and the feel of the brake pedal. As the running in process progresses, the brake pads and brake discs gradually adapt to each other, with tighter and more uniform contact. The braking performance will gradually improve, and the height of the brake pedal will also tend to be normal.