What Causes the Handbrake to Lock Up in the Rain?
2 Answers
Handbrake lock-up in the rain occurs when the handbrake is engaged after driving through water, and the brake pads and brake drums rust and fuse together after prolonged parking. When the vehicle cannot be stopped using the foot pedal brake, pulling the electronic handbrake switch for more than 2 seconds will activate emergency braking, accompanied by a warning signal. Releasing the handbrake switch or pressing the accelerator pedal will cancel the emergency braking. The car's electronic handbrake, also known as the Electronic Parking Brake (EPB), is marked with a "P" button on the vehicle. Its working principle is the same as that of the traditional mechanical handbrake, both achieving parking control through the friction generated between the brake disc and brake pads. The only difference is that the control method has changed from the previous mechanical handbrake to an electronic button. Method to activate the electronic handbrake: Press the brake pedal and pull the electronic handbrake switch upward until the indicator light on the dashboard lights up, and the indicator light on the handbrake switch will also illuminate. If the vehicle is turned off without activating the electronic handbrake, the system will automatically engage it. Method to deactivate the electronic handbrake: While pressing the brake pedal, press the electronic handbrake switch, and the indicator lights on the dashboard and the switch will turn off. Pressing the accelerator while the engine is running can automatically release the electronic handbrake.
After the last rain, the handbrake got stuck, and even as an experienced driver, I found it annoying. Moisture caused the brake discs to rust and stick, especially when parked on wet and slippery ground, as oxidation of the metal parts increases mechanical resistance. Normally, I don’t always use the handbrake on rainy days; instead, I park in P gear for automatics or in gear for manuals to avoid rust. It’s advisable to drive for a while after parking to let the brakes heat up and dry, or use rust-removal spray for regular maintenance to prevent worsening rust that could affect the next start. Long-term neglect may lead to brake seizure and difficulty moving the wheels. Before the rainy season, it’s best to check the brake discs and cables—cleaning and lubricating are great rust-prevention tricks, and it’s simple for those who are handy.
