Q: How to remove, overhaul, and refit rear brake calipers on Toyota Yaris?
A: Chock the front wheels, jack up the rear of the vehicle, and support it on axle stands before removing the rear roadwheels. Fully release the handbrake lever and unscrew the adjustment nut to provide slack in the handbrake cable. Using a screwdriver, press down the handbrake lever on the back of the rear caliper, then disconnect the outer cable from the support bracket by rotating the toothed wheel on the outer cable to release the retaining clip. Clean the area around the caliper brake hose union, unscrew and remove the union bolt, and recover the sealing washer from each side of the hose union, discarding the washers as new ones must be used on refitting. Plug the hose end and caliper hole to minimize fluid loss and prevent dirt ingress into the hydraulic system, then remove the brake pads. If necessary, unbolt the caliper mounting bracket from the trailing arm. Brake calipers have an aluminium cylinder bore that cannot be honed; if scoring is evident, a stainless steel sleeve must be pressed into the cylinder with a new piston used, making overhauling a caliper more expensive than replacing it with a new or re-manufactured one that comes with a warranty. If still intending to overhaul, check on the availability of parts before beginning. Where removed, refit the caliper mounting bracket to the trailing arm, apply locking fluid to the threads of the mounting bolts, insert them, and tighten to the specified torque. Clean the caliper upper swivel pin, apply silicone grease, slide the caliper into its upper guide bearing, and refit the brake pads. Position a new copper sealing washer on each side of the hose union, connect the brake hose to the caliper, ensure correct positioning, then insert the union bolt and tighten it to the specified torque. Remove the brake hose clamp or polythene, and bleed the hydraulic system, noting that it should only be necessary to bleed the relevant rear brake circuit if precautions were taken to minimize brake fluid loss. Refit the handbrake cable to the support bracket and secure it with the retaining clip, press down the handbrake lever, and reconnect the end of the cable. Depress the brake pedal several times to ensure the brake pads are set to their normal position, adjust the handbrake cable, then refit the lever gaiter. Refit the roadwheels, lower the vehicle to the ground, and tighten the roadwheel bolts to the specified torque. Finally, check the brake hydraulic fluid level.