What causes a popping sound when releasing the handbrake to start the car?
3 Answers
There are two main reasons for the popping sound when starting the car: The sound originates from a single brake system. If not addressed promptly, it may affect all brakes. This occurs when moisture is not dried in time after washing the car or driving through water, causing the brake caliper piston or shoe block to fail to return to position. Other causes of abnormal noises during startup include: In southern regions, due to the humid and rainy climate during spring and autumn, prolonged driving in such conditions can gradually cause the brake discs to rust. Vehicles with water-soaked chassis are particularly prone to brake disc oxidation and rust. In this case, simply ask a technician to sand off the rust from the brake discs during maintenance to eliminate the abnormal noise. Foreign objects trapped in the tire treads, such as screws, stones, or other hard objects, can cause noise. Removing these objects from the tires will resolve the issue. Chassis-related issues are among the most common faults. Many cars develop suspension aging after prolonged use. At this point, some supporting components in the suspension gradually fail, causing the chassis to make abnormal noises during startup. It is advisable to visit a 4S shop or professional repair facility for chassis maintenance and inspection to check for loose, aged, or leaking bearings and replace any faulty parts promptly.
I've been driving for over 20 years, and this kind of popping sound is very common. It's usually caused by the handbrake not being fully released, especially when parked on a slope with the handbrake pulled too tight. The brake pads sticking to the rotors in humid conditions can cause this sound when they suddenly release upon starting, which happens more often after washing the car in winter. If the sound persists for several consecutive days, it's necessary to check the handbrake cable, as it might be rusted or stuck and require lubrication. For automatic transmission cars, it's recommended to put them in P gear without using the handbrake, while manual transmission cars should be left in gear after turning off the engine, which is both safe and prevents strange noises. Last time my car made this noise, the mechanic applied some lubricant to the cable during maintenance, and the problem was solved.
Last month, my car had the same issue, especially noticeable after rain. A mechanic friend said it was the handbrake pads sticking to the brake discs, causing a metallic sound when forcibly separated during startup. Later, I found that not pulling the handbrake too hard when parking and simply leaving it in gear on flat ground is more convenient. If the noise is accompanied by vibration, it might be due to rusted spring clips getting stuck. Once, a technician at the 4S shop demonstrated that lightly pressing the brake pedal twice after releasing the handbrake helps the brake pads reset, reducing the noise. Remember to perform regular brake maintenance; cleaning the mud and rust between the discs and pads is essential.
