What causes severe shaking when the vehicle brakes?
4 Answers
During vehicle use, you may feel the car shaking when applying the brakes, while driving normally there are no issues. This situation is generally caused by problems with the brake discs. This is because, strictly speaking, the brake discs have become deformed. Brake discs also require dynamic balancing, but the requirements for brake disc balancing are even stricter than those for tires. Reasons why brake discs cannot maintain dynamic balance: 1. Uneven wear on the brake discs, meaning severe wear on one side. This is due to issues with the vehicle itself, primarily caused by poor retraction of the brake caliper. Car braking is achieved by two friction pads pressing against the brake disc through the caliper to create friction and braking effect. Since the brake is only connected to the inner friction pad, incomplete retraction of the caliper after braking will lead to increased wear on one side. 2. Use of low-quality brake pads. Inferior brake pads contain a large amount of metal substances. When these metal substances come into contact with the brake disc, because they are harder, the brake pads wear more slowly (they are meant to wear) but will reduce the lifespan of the brake disc. Solutions: 1. Replace the brake discs. This can be decided based on the condition of the brake discs. If the brake discs are already heavily worn, it is recommended to replace them altogether. 2. Machine tool processing. After removing the brake discs, give them to a professional machinist for deep processing to restore their dynamic balance.
A few days ago, I encountered the same situation while driving on the highway—the steering wheel shook violently when braking. The main issue lies with the brake discs, where uneven or warped surfaces are the most common causes, often due to high-temperature deformation from repeated hard braking. It could also be caused by uneven wear of the brake pads, leading to imbalanced friction. Additionally, loose suspension components like ball joints or control arms can trigger shaking. Last time at the repair shop, the mechanic first measured the thickness of the brake discs and then resurfaced them on a lathe. Actually, just being mindful in daily driving helps—avoid slamming on the brakes too often, especially when going downhill; use engine braking more to protect the brake discs. Regular brake system inspections are crucial; it’s best to check the condition of the brake discs and pads every 20,000 kilometers.
As a seasoned driver with over a decade of experience, brake vibration usually stems from three main sources: Warped brake rotors are the most common culprit, especially after sudden braking when driving through water in rainy conditions, causing uneven cooling. Next are brake pad issues – improperly installed aftermarket parts or overly hard materials can both cause problems. Then there's loose wheel hub bearings, where the brake rotor wobbles during rotation. Just last week, a neighbor's car exhibited this – at 80 mph, the steering wheel shook violently during braking, and upon inspection, the wheel hub bolts weren't even tightened properly, which is extremely dangerous! Always double-check wheel installation after tire repairs. A good diagnostic tip: If the pedal pulsates, it's likely ABS activation; steering wheel vibration indicates suspension or rotor issues, while whole-body shaking suggests wheel balance problems.
Last time during maintenance, the technician told me that brake shudder is mostly a problem with the braking system. The most common issue is brake disc deformation due to high temperatures, especially with disc brakes. A stuck caliper can also cause excessive braking force on one side. Additionally, wheel hub deformation is even more dangerous. Once I hit a pothole without slowing down, and the wheel hub got a small dent, causing noticeable shudder when braking. It's also important to check tire wear, as uneven tread can transmit vibrations during braking. The repair is simple: resurfacing deformed brake discs costs around 100-200 yuan; severely deformed discs need replacement. Issues with tires or wheel hubs require a wheel alignment. A reminder to everyone: slow down when going over speed bumps to avoid wheel hub deformation.
