What to Do When Drum Brakes Lock Up and Don't Release?
2 Answers
Solutions for drum brakes locking up and not releasing include replacing the master cylinder cup, adjusting the fit clearance, replacing the brake piston, and replacing the brake disc. Drum brakes locking up and not releasing usually occur in vehicles without ABS anti-lock braking systems. In cars without ABS, if the brake pedal is pressed hard while driving, the wheel speed will rapidly decrease. When the braking force exceeds the friction between the wheels and the ground, the drum brakes will lock up and not release, causing the fully locked wheels to increase friction between the tires and the ground. Under significant inertia, this may lead to skidding and loss of directional control. Drum brakes locking up and not releasing are caused by excessive braking force between the brake pads and the disc or brake drum. However, due to the vehicle's high inertia, the car continues to move forward, with the tires sliding rather than rolling, making it impossible to change direction and potentially causing accidents. Even with low inertia, on crowded or busy roads, if following another vehicle too closely, drum brakes locking up and not releasing can cause sudden stops, increasing the risk of rear-end collisions.
I've been driving for almost thirty years and have encountered several instances where the drum brakes locked up and wouldn't release, mainly due to rust and seizing from rainy weather or long periods of inactivity. That time on the mountain road, the brakes suddenly locked, and I quickly pulled over and turned off the engine. I tried lightly tapping the brake drum a few times to help loosen it. If there's no response, don't force it to drive, as overheating the wheel can cause more severe damage. I also usually try slowly reversing a few meters to see if it releases, but this trick only works temporarily. It's best to call a tow truck immediately for repairs. A professional mechanic can check if the brake shoe springs are broken or if the adjustment screw position needs tweaking. Regular maintenance is crucial—I personally clean the brake components or spray some anti-rust agent every quarter to prevent issues and avoid risking accidents on the road.
