What Causes the Noise When Braking Just After Starting the Car?

[Andrea]

When you slowly release the brake pedal, the engine already has enough power to drive the car forward, but your brakes haven't fully disengaged yet. As a result, the moving wheels are being held back by the braking system, which naturally produces unusual noises—this is a normal phenomenon. Here's some relevant information: In manual transmission cars, when you lift the brake, the transmission doesn't output power, and the vehicle starts only after the brake is fully released. However, in automatic transmission cars, as soon as you engage the gear, the transmission already provides the force for the tires to rotate forward; it's just that the brakes are being pressed, preventing the vehicle from moving. When starting an automatic transmission car, the brake is usually released slowly. If you release the brake quickly, you won't hear this noise.

[DiAnnie]

My car makes a squeaking noise when braking at startup, and I've encountered this issue several times myself. Generally, the sound may be caused by rust or dirt between the brake pads and rotors, especially after the car has been parked overnight, as moisture can condense on the rotor surface and cause rust. The first few brake applications after startup may produce a creaking noise, but it usually disappears after driving for a few minutes as the brakes warm up. Another common situation is that newly replaced brake pads require a break-in period, initially emitting a light humming sound. If this persists for one or two weeks, it might indicate improper installation or loose components. Severely worn brake pads can also make noise when the metal wear indicators are exposed, resulting in a sharper squealing sound. I recommend avoiding parking in damp areas and gently pressing the brakes a few times to warm them up before driving. If the noise becomes louder or occurs more frequently, it's crucial to visit a repair shop immediately for inspection, as neglecting it could pose serious safety risks—just like the close call I had due to my previous oversight.

[Phoebe]

When the brakes make noise upon activation, here's my DIY maintenance perspective. First, the most common cause is rust on the brake disc surface or debris stuck between the pads. For example, after parking for a long time in the rain, the disc rusts and causes a humming sound when rubbing. During self-inspection, check for rust spots on the disc after parking and try wiping it with a cloth. Another possible source is worn-out brake pads; the wear indicator on the pads will emit a whistling sound to remind you to replace them. I usually measure the thickness every six months—if it's worn down to 3mm, it's time to replace them. Additionally, insufficient lubrication on the caliper slide rails can prevent the pads from retracting smoothly, causing a sticking noise when starting. Just apply some high-temperature grease yourself. However, be careful not to tamper unnecessarily—if there's brake fluid leakage or air in the system, the sound will be even stranger and require professional attention. In short, regular maintenance can reduce this issue, saving money and ensuring peace of mind.

[MacAdalynn]

Having driven for over 20 years, it's quite common to hear noises when braking at the start. The main reason is often rust on the brake discs after the car has been parked for a long time, especially during rainy seasons or cold weather. The first press of the brake pedal causes a rumbling sound due to friction, but it disappears once the car warms up. Another possibility is aged brake pads or small stones and sand particles embedded in them, which produce a sharper sound. It's important to regularly check the brake system and not wait until the noise becomes louder—safety comes first. Usually, rinsing the wheel hubs during car washes to prevent dust buildup can help prevent this.