What causes brake failure in the Changan Benben New Energy e-star?

[VanAthena]

Benben E-Star has experienced batch issues with the brake vacuum booster pump, resulting in the brake pedal becoming stiff during driving, making it difficult to press down, leading to reduced braking effectiveness and a sensation of brake failure. The role of vacuum assistance: Unlike traditional gasoline-powered vehicles, the vacuum assistance in new energy vehicles does not come from the vacuum generated by the engine's intake system during operation, as most new energy vehicles do not have an engine. To leverage mature component systems as much as possible, many new energy vehicles opt to use an electric pump to simulate the engine's vacuum assistance. The vacuum pump maintains the vacuum level in the assistance system at several tens of kilopascals or higher to provide sufficient braking support. Vacuum assistance failure: When the system's vacuum level drops, the electric pump activates to replenish the vacuum, which is why many new energy vehicles produce intermittent operational noise.

[IsabelleFitz]

As someone who frequently drives new energy vehicles, the issue of brake failure in the Changan Benben e-star can be analyzed from several perspectives. New energy vehicles are equipped with a kinetic energy recovery system. If this electronic control system malfunctions, the deceleration effect when releasing the throttle will diminish. Additionally, if the brake booster pump operates abnormally, the brake pedal will feel unusually hard when pressed. Sometimes, wheel sensors covered in mud can transmit incorrect signals, affecting the performance of the anti-lock braking system. Moreover, low brake fluid levels or oil leaks in the pipelines can lead to sudden brake failure. These situations are more likely to occur in humid weather or after prolonged parking, and professional equipment is required to read fault codes for accurate problem identification. Regular maintenance is essential: brake fluid should be replaced if it turns black, and wheel sensor wires should not be tampered with casually.

[MacMaya]

I experienced sudden brake softening while driving the BenBen E-Star, which was later found to be related to new energy vehicle characteristics. The electronic power brake relies on the 12V auxiliary battery for power—when the battery reaches the end of its lifespan and voltage becomes unstable, it affects brake assist. Interference from the energy recovery system is also common, where automatic deceleration upon releasing the throttle fails to engage. Uneven brake pad wear can cause caliper sticking, especially with frequent short-distance driving. I recall one instance after rain when the brake discs rusted, causing friction noise at startup and affecting braking force. For such issues, it's recommended to test the brake fluid's water content at every service—replace immediately if it exceeds 3%. New energy vehicles have shorter maintenance intervals than fuel cars, so don’t overlook brake pad thickness checks.

[OBrynlee]

The significant inertia of new energy vehicles highlights the importance of system interconnectivity in braking failures. When energy recovery systems malfunction, braking force relies entirely on mechanical brakes, where sudden load increases can easily cause issues. Overheated brake pads leading to thermal fade are particularly hazardous during continuous downhill driving. A loose or leaking vacuum booster connection requires full pedal force to be effective. Sometimes, automatic vehicle system updates can interfere with the brake control unit. It's advisable to keep the brake pedal ready even when using one-pedal mode, maintaining room for mechanical braking. In case of failure, shifting to P gear can help decelerate, but avoid doing so at high speeds; it's only safe below 40 km/h. Maintenance should ensure no mixing of different brake fluid types to prevent seal corrosion.