What Causes the Brake Pump to Not Retract?
2 Answers
Brake pump not retracting is caused by wear and tear on the brake discs and pads or a malfunction in the left and right brake calipers of the braking system. Wear and Tear on Brake Discs and Pads: Wear and tear on the brake discs and pads refers to the loss of surface flatness after prolonged use, leading to misalignment. This causes the brake pump to not retract. Solutions include resurfacing the discs using a lathe or replacing the brake pads. Malfunction in Left and Right Brake Calipers: This issue, commonly known as 'uneven braking,' occurs when the left and right brake calipers apply uneven force to the brake pads. It happens because the brake discs rotate at high speeds during driving, and the calipers do not exert uniform pressure.
The issue of the brake caliper not retracting is actually quite common. Last time I had my car repaired, the mechanic told me it's most likely due to the piston inside the caliper getting stuck. Contaminants in the brake fluid or the fluid deteriorating and forming clumps can block the piston just like a clogged blood vessel. Another possibility is a broken return spring—though small, it plays a crucial role in retracting the brake pads. If the caliper guide pins rust or lack lubrication, they can also seize up. I once saw a car whose pins rusted into a solid lump after getting soaked in rainwater. The worst-case scenario is a faulty master cylinder, which requires disassembling the brake lines and is particularly troublesome. If this happens, never force the car to drive. My colleague once drove halfway with the brakes stuck and nearly rear-ended another car. The best solution is to call a tow truck and take it to a professional repair shop.
