Is it normal for the ABS pump of the new Sagitar to make a noise when starting?
2 Answers
It is normal for the new Sagitar's ABS pump to make a noise when starting. This is because the ABS pump operates to build up system pressure and perform a self-test, during which the sound of the ABS pump running can be heard. ABS, short for Antilock Brake System, functions by automatically controlling the braking force during vehicle braking to prevent wheel lock-up, keeping the wheels in a state of rolling and sliding (with a slip ratio of around 20%), ensuring maximum adhesion between the wheels and the road. Working principle: During braking, the ABS quickly determines the lock-up state of each wheel based on speed signals from the wheel speed sensors. It closes the normally open input solenoid valve on the wheel that is starting to lock up, maintaining the braking force. If the wheel continues to lock up, the normally closed output solenoid valve is opened, causing the braking pressure on that wheel to drop rapidly due to the direct connection to the brake fluid reservoir, preventing the wheel from fully locking up due to excessive braking force. This keeps the braking state at the optimal point (slip ratio S of 20%), achieving the best braking effect and ensuring the highest level of driving safety.
I've been driving the new Sagitar for almost half a year now, and sometimes there's a slight sound from the ABS pump when starting, which is mostly normal, especially during cold starts or on slippery roads. The ABS system performs a self-check before activation, occasionally producing a slight vibration sound, but it doesn't affect braking performance. If the sound only occurs once during startup without any accompanying shaking or brake failure, there's generally no need to worry. From my experience, this is a common design in Volkswagen models to ensure braking stability. However, if the sound becomes louder or occurs every time, it's advisable to check the brake fluid level and whether the pump assembly is aging to avoid potential issues. Regular maintenance is important to prevent debris from affecting the system.
