Why does the car make noise when the handbrake is released?
3 Answers
Relationship between abnormal noise and engine speed Most common abnormal noises in the engine depend on the engine's speed state. 1. The noise only exists at idle or low speed. Possible causes include: excessive clearance between the piston and cylinder wall; overly tight piston pin assembly or connecting rod bearing assembly; excessive clearance between the tappet and its guide hole; wear on the camshaft profile; sometimes, a loose starter clutch causing pulley noise (more noticeable during speed changes). 2. The noise becomes chaotic at a certain speed, with brief sounds occurring successively during rapid deceleration. Possible causes include: cracked camshaft timing gear or loose fixing nut; broken crankshaft; loose piston pin bushing; excessive axial clearance of the camshaft or loose bushing. 3. The noise appears during rapid engine acceleration and persists at high speeds. Possible causes include: loose connecting rod bearings, melted or mismatched bearing shells; loose crankshaft bearings or melted bearing shells; broken piston pin; broken crankshaft.
I recently encountered the same issue with the parking brake making noise when released. After having a mechanic check it, I found out it was because the brake pads were worn too thin. The small metal piece was directly scraping against the brake disc, causing a squealing sound when driving, as if reminding me it was time to replace the brake pads. Another time, I discovered the parking brake cable was stuck, possibly due to rust after driving in the rain, preventing it from returning to its original position, so the wheels were slightly braked all the time. Additionally, a faulty parking brake switch can also cause this issue—it keeps alarming as if the parking brake is still engaged. A friend of mine had an even more bizarre situation where the parking brake was adjusted too tightly during the last maintenance, so even when released, it wasn’t fully disengaged. All these scenarios can cause the car to make sharp noises or trigger warning lights on the dashboard while driving. Never ignore these signs—brake issues are not to be taken lightly, as they can dangerously affect braking distance if left unresolved.
This issue is frequently handled in the workshop. When the car's handbrake is released and it makes noise, the most common cause is the rear brake pads wearing down to their limit, where the warning shim rubs against the brake disc, producing a metallic scraping sound that resembles a hissing or squeaking noise. It could also be due to the return spring of the mechanical handbrake cable rusting and seizing, preventing the brake shoes from fully releasing, which can be felt as noticeable resistance when lifting and turning the wheel. For electronic handbrake systems, it's necessary to check whether there's a conflict between the motor controller and the wheel speed sensor signals. In some older cars, the issue might be poor contact in the handbrake base switch, causing the alarm to sound even when the handbrake is released. The simplest method is to first feel the temperature of the wheel hubs; if one wheel is particularly hot to the touch, it's likely not releasing properly. For safety reasons, it's important to resolve this issue promptly, as it can lead to increased fuel consumption and damage to the brake discs.
