Rear Brake Caliper Piston Retraction Techniques?
3 Answers
To retract the rear brake caliper piston, rotate the rear brake pads until they can accommodate the brake pads, ensuring that the brake pads and brake disc align properly, which indicates successful rotation and retraction. Below is relevant information about the brake caliper: 1. Function: The brake caliper is an essential chassis braking component in the braking system, primarily responsible for pushing the brake pads, which then frictionally engage the brake drum to reduce speed or bring the vehicle to a stop. 2. Working Principle: ① Passenger Cars: When the brake pedal is pressed, the outlet port opens while the inlet port closes; when the brake pedal is released, the outlet port in the master cylinder closes and the inlet port opens. ② Trucks: The air pump, driven by the engine, compresses air into high-pressure gas stored in the air reservoir. One of the reservoirs is connected to the brake master cylinder via pipelines.
For retracting the rear brake caliper piston, I often do this myself and find that using a C-clamp is the most reliable method. Clamp it onto the caliper and slowly tighten to push the piston back—don’t rush, or you might damage the seal. Remember to open the brake fluid reservoir cap first to release pressure, making it easier to push. If you don’t have the tool, try carefully pushing with a wrench wrapped in cloth. Also, check if the caliper is worn; if the piston is stuck, don’t force it—you might need a replacement. I recommend cleaning the caliper during routine maintenance to prevent dust from causing retraction issues, saving hassle during the next brake pad change. Investing 20-30 yuan in a dedicated piston tool is well worth it.
I always pay attention to safety when repairing cars. Before pushing the piston, I must disconnect the battery to avoid accidentally lighting up the brake lights or causing a short circuit. Push slowly and steadily, using simple tools like a wrench to apply even force, and avoid using brute force to pry to prevent deformation of the brake caliper. The brake fluid reservoir should be opened; otherwise, it will be difficult to push and may cause oil overflow. If the piston gets stuck, don’t force it—check if the seal is leaking or if there are any foreign objects. Maintaining the caliper in good condition prevents problems, and developing good habits saves trouble.
