Why can't the car stop after replacing the brake pads?
3 Answers
If the car cannot stop properly after replacing the brake pads, it is because the surface of the new brake pads is not perfectly smooth. Small protrusions on the surface will make initial contact with the brake disc, reducing the contact area and friction. This issue will resolve after a break-in period. More details are as follows: 1. The brake pads are a crucial component of the braking system and are also a wear-and-tear part. It is normal to experience reduced braking force immediately after replacing them. 2. Automotive brake pads, also known as brake linings, are friction materials fixed to the rotating brake drum or disc. The friction lining or block withstands external pressure to generate friction, thereby achieving vehicle deceleration.
I've also experienced the situation where the brakes don't hold well after changing brake pads, and there are quite a few reasons for this. Incorrect installation is key, such as installing the brake pads backwards or not securing them properly, which affects friction performance. New pads and brake discs require a break-in period, and it takes a few hundred kilometers of driving for the performance to stabilize. In the initial stage, there might be some slippage, and the braking force may be weaker. When the brake disc surface is contaminated with oil or unevenly worn, the new pads won't adhere well, reducing effectiveness. If air accidentally enters the hydraulic system during the brake pad replacement process, the brake pedal may feel loose and ineffective. I recommend driving at low speeds after replacement and performing several gentle brakes to test, avoiding sudden acceleration or hard braking. If the problem persists, it may indicate poor pad quality or incorrect sizing, and you should promptly visit a professional shop to bleed the brakes and check the brake fluid lines and disc surface condition. Safety comes first—don't delay repairs to avoid accidents on the road.
When helping with car repairs, I often encounter cases where newly replaced brake pads fail to stop the vehicle properly. Improper installation is the main cause: brake pads installed in the wrong direction or loose, leading to uneven friction. The brake discs not being thoroughly cleaned, leaving old debris or grease residue, affects the new pads' grip. New pads initially have unstable performance and need to be run-in for a few hundred kilometers to fit properly. Air entering the hydraulic system can cause the oil to compress and deform, resulting in weak braking. During inspection, check if the brake fluid level is correct and if the pedal feels soft. If you're doing it yourself, ensure the pads are installed correctly, the discs are thoroughly cleaned, and the system is fully bled. After replacement, gently press the brakes a few times to break them in and avoid sudden stops. If the problem persists, there might be a leak in the lines or an issue with the pump—get it repaired immediately and don't take risks. Remembering these small details can save you from big troubles and reduce risks.
