What Causes the Rear Brake of a Motorcycle Not to Retract?
4 Answers
The main reasons why the rear brake of a motorcycle does not retract are: 1. The brake is corroded and cannot return smoothly, and the spring's elastic force cannot overcome the resistance caused by corrosion. Using a cleaning agent to clean it can restore functionality. 2. Water entering the brake fluid causes the piston in the wheel cylinder to rust. Here is some additional information: 1. The principle of disc brakes: Disc brakes use stationary brake calipers to clamp the rotating brake disc attached to the wheel, creating friction to reduce the wheel's rotation speed. When the brake pedal is pressed, the piston in the master cylinder is pushed, creating pressure in the brake fluid circuit. 2. Advantages of disc brakes: (1) Disc brakes dissipate heat better than drum brakes, making them less prone to brake fade and failure during continuous braking. (2) The thermal expansion of the brake disc in the thickness direction is minimal, so heat-induced size changes do not increase the brake pedal travel. (3) Disc brake systems respond quickly and can perform high-frequency braking actions, making them more suitable for ABS system requirements.
I've been riding motorcycles for nearly twenty years, commuting daily and hitting mountain roads on weekends. Once, my rear brake pedal didn't spring back after being pressed, which scared me into pulling over immediately. Upon inspection, I found the small spring in the drum brake had snapped. When the spring breaks, the brake shoe sticks to the drum and won't release. Possible causes include accumulated mud not being cleaned, leading to rust and breakage of the spring, or simply wear and tear over time. This tends to happen if you don't clean the bike after riding in the rain. After the repair, I recommend checking the brake system during seasonal maintenance, especially the springs and cables—never cut corners when it comes to safe riding.
As someone who frequently repairs motorcycles, I've seen the issue of the rear brake not retracting many times. Common causes include the brake cable being rusted or deformed and unable to pull, or hydraulic fluid being dirty causing the piston to stick. Sometimes, the return spring is fatigued or broken, leaving the brake pads stuck in position. A simple way to diagnose: if the brake feels heavy and lacks elasticity when pressed, first check the fluid reservoir's level and color. If the fluid is low or black, replace it immediately. You can try cleaning the components yourself, but for more complex issues, it's best to seek professional help. Regular maintenance is key, especially in dusty urban environments where components get dirty more easily.
Rear brake not retracting is really dangerous. When encountering this issue while riding, unstable braking can easily cause skidding or collisions. It might be due to spring fatigue and breakage, cable jamming, or contaminated hydraulic fluid preventing retraction. I once nearly had an accident because I didn't promptly repair a loose spring. If discovered, you must stop immediately and not risk riding further. Safety first—it's recommended to have professional brake inspections twice a year. Although there are many potential causes, prevention is key. Don't wait until an accident happens to regret it.
