Brake pads should squeeze the disc brake rotor and release it without the pads dragging. When a caliper piston continues to push the brake pad against the rotor you need to know how to loosen the brake pads to correct the problem. The reason for a brake pad dragging across the rotor could be a result of worn seals around a brake caliper piston inside one or more disc brake calipers.
Instructions
- Loosen the lug nuts one-half turn before lifting the vehicle off the ground. Jack the vehicle off the ground with a floor jack and set it onto jack stands positioned under the frame near each wheel. Remove the wheel when the vehicle is off the ground and lowered onto jack stands.
- Cover your nose and mouth with a dust mask. Use an Allen wrench to loosen the brake caliper mounting bracket. Reach around the caliper to find the bolts that secure the caliper to the mounting bracket. Insert the end of the Allen wrench into the Allen-head bolt and turn clockwise to loosen. Repeat for the other retaining bolts and pull the loosened bolts free of the caliper and the mounting bracket.
- Grab the caliper and pull it free from the rotor. The caliper with brake pad needs to be pulled away from the edge of the rotor to free the caliper. Remove the caliper and hold it up with your hands until you can set it in a place that doesn't stretch the short rubber brake line connected to it. Set the caliper on the axle near the rotor to rebuild it without separating the brake lines from the calipers when you do.
- Pull the old brake pads out of the caliper. They sit on the pistons with a metal clip that holds them on the end of the piston with friction. Just pull the pads off the pistons to remove. Depress the brake pedal inside the car to push out the caliper pistons you will be rebuilding. Remove the retaining pin located in the side of the piston and pull the piston out of the caliper.
- Clean the outside surface of the caliper piston with 400-grit Emery cloth. Remove the old piston seals that wrap around the piston and replace with a new rubber O-ring seal. Grease the outside surface of the piston before inserting it back into the caliper and tighten the retaining pin in place before moving to the next piston.
- Depress the brake pistons using a C-clamp when you need to install new brake pads after rebuilding the brake caliper pistons to loosen brake pads. Assemble the caliper with new brake pads and slip the caliper and pads over the rotor. Secure the caliper to the mounting bracket. Depress the brake pedal to work the new caliper pistons.
- Bleed the caliper. Insert one end of a bleeder tube over the bleeder valve on the caliper and the other end inside a soda bottle with three inches of new brake fluid inside. Depress the brake pedal and loosen the bleeder valve to let fluid escape the caliper and flow into the bottle. When no air bubbles are present the system is effectively bled.
- Repeat the process for all stuck brake pads. Replace the wheels and lower the vehicle back on the ground to finish. Test and bleed the brake system to return the system to like-new condition.
