What are the causes of brake drag?

[Luke]

When a car is in motion, after pressing the brake pedal and then releasing it, the braking should be quickly disengaged. If the braking effect persists after releasing the pedal and cannot be quickly disengaged, this phenomenon is called brake drag. The following are the causes of brake drag: 1. The brake pedal has no free travel or the return spring is detached, too soft, or broken; 2. The rubber cups and rings of the hydraulic master cylinder are swollen, and the return spring is weak, causing the rubber cup to block the balance hole, preventing oil return or reset; 3. The rubber cup of the hydraulic wheel cylinder is swollen or the wheel cylinder is not moving freely; 4. The gap between the friction lining and the brake drum is too small; 5. The brake shoe support pin is dirty, preventing the brake shoe from rotating freely, or the oil pipe is clogged with dirt, causing poor oil return.

[BarrettDella]

I often deal with brake drag issues. If the brake caliper piston rusts or gets stuck, and the lubricant fails, the brake pads will stick and not move. Additionally, damaged wheel hub bearings can cause the entire system to skew, increasing friction. Poor rebound of the emergency brake cable is also a major hazard, especially after washing the car when water ingress can cause rust. Moreover, when air or contaminants mix into the brake hydraulic fluid, the system fails to fully release pressure, causing the piston to drag. Changes in chassis height or improper modifications can also lead to abnormal friction. If you notice dragging, stop driving immediately—overheating from friction can easily cause a tire blowout or loss of control, which is very dangerous. It's recommended to check monthly whether the wheels rotate smoothly, as rust prevention and cleaning can save a lot of money.

[EmmettRose]

Brake dragging commonly occurs when the braking system fails to fully reset, such as when the caliper guide pins are corroded and seized, causing the brake pads to stick to the rotor. Blocked brake lines or improperly adjusted brake shoes can also be contributing factors, leading to noticeable abnormal noises or resistance when the wheels rotate. If left unrepaired, fuel consumption can skyrocket—I've observed an average increase of 10% during long-distance driving—while also accelerating wear on other components, resulting in costly repairs. Environmentally, the additional resistance increases emissions and pollution. Regularly check if tire temperatures rise and address issues promptly before they cause serious damage.

[RichardRose]

As a seasoned driver with over a decade of experience, I've found that brake dragging is mostly caused by minor issues. Simply put, it could be due to poor return of the brake cable or springs, especially when they rust after humid weather. Aging piston seals that leak oil can cause the brake pads to stick together due to oil contamination. Additionally, warped or uneven brake discs, or mismatched aftermarket wheels with too small a gap can lead to dragging. Make it a habit to check if the wheel hubs are hot after each stop—early detection can prevent major repairs. Safety always comes first.