The procedure below is for either the front or the rear brake calipers. However, if an overhaul is necessary, provided primarily because of leakage, one should consider all the possibilities before starting the process. Luckily, new and factory rebuilt brake calipers can be procured at cutters on an exchange basis, so this is not a small job. If the decision to rebuild the brake calipers is made, make sure that before proceeding there is a rebuild kit for this work. Beginning with the removal of brake line from the brake caliper and fitting a plug to guard against any debris from getting into the brake system or to reduce on brake fluid loss. On the rear brake caliper, to release the parking brake pull the clevis pin outward and remove the C-clip and then pull the brake caliper off the brake caliper guide pin. To pull out the brake caliper, first take the retaining ring out of the rubber boot, and then take the rubber boot out, use a wooden block to place it in-between the piston and brake caliper so that the piston does not suffer while removing it. To clean the brake caliper, blows air into the piston to detach it from the brake caliper and examine the mating area of the piston for indications of scoring, rust, pits or brightness; if these are observed, replace the complete brake caliper. If the components are healthy, then carefully un-bolt the rubber seal, which is located in the brake caliper bore, without spoiling it. Take the sliding bushing out of the brake caliper housing and pull the two rubber boots off from both extremities; pull the bushing sleeve also out. Clean all components with clean brake fluid or alcohol. For reassembly, the right rebuild kit should be used and for the bushing sleeve when screwing it back into the vehicle body, apply the silicone-based grease on the sliding bushing. Place the new rubber seal and piston in the brake fluid, then set them in the brake caliper bore with the piston being profoundly seated prior to applying pressure. Fit the new rubber boot and retaining ring. Because it involves the use of special tools to disassemble and overhaul the rear disc brake caliper, it is advised that this task be left to a dealer service department; however, you may re-attach it after it has been overhauled or fitted with a rebuilt one. Lift the rear of the vehicle and securely supporting it on jackstands, turn the front wheels to prevent rolling and take the rear wheels off. Last, turn the brake caliper clockwise back into position and unscrew the copper sealing washer on the brake line union bolt and tighten, while disregarding the lock nut; if necessary, bleed the brake circuit.
Posted by ToyotaPartsDeal Specialist 
