What to Do When the Caliper Piston Doesn't Retract?
3 Answers
Caliper piston not retracting may indicate an issue with the brake pads, and it's advisable to visit a 4S shop for repairs. The brake caliper is the component that applies force to the brake disc, with the hydraulic pressure generated by the master cylinder ultimately acting on the piston inside the caliper. In ordinary family cars, the brake caliper piston is located on only one side of the caliper, and from the outside, only the caliper and the brake pads fixed to it are visible.
When I find that the caliper pistons aren't retracting, I usually check them myself. First, remove the wheel and carefully observe the piston position, then try to gently push it back. If it doesn't move, it might be due to rust or dirt buildup inside the piston cylinder. In that case, spray some specialized cleaner and lightly apply lubricating oil. If that still doesn't work, consider whether the piston seals have aged or been damaged—then replacement parts are necessary. The whole process requires patience, but remember safety first—driving with brake issues is dangerous, so ensure the car is parked stably and the jack is securely positioned before starting. Regularly replacing brake fluid also helps prevent corrosion caused by moisture infiltration. DIY repairs can save money, but if you lack experience, it's better to leave it to professional technicians to avoid making things worse.
When dealing with the issue of a caliper piston not retracting, I take safety very seriously as it directly affects braking performance. The first step is to stop the vehicle immediately and not drive it further, then arrange for a tow to a repair shop for inspection. Common causes include rust in the piston cylinder, excessive impurities in the brake fluid, deformed seals, or oil and dirt clogging the moving space. At the shop, technicians will use professional tools to clear blockages and, if necessary, replace the piston or the entire caliper. I also remind myself to focus on prevention in daily use, such as avoiding long-term parking in damp areas to prevent rust, and rinsing the brake components during car washes to remove dirt. Brake system maintenance should never be taken lightly—if not repaired promptly, it can lead to dragging rotors, overheating, or even fire risks during the next brake application. Staying vigilant with regular maintenance can help avoid future troubles.
