If it seems that an overhaul is necessary due to leakage, a stuck piston or a broken bleeder screw check all the available possibilities before starting the process. It is relatively easy to order new or factory rebuilt calipers to be used on an exchange basis. When replacing calipers make sure to have rebuild kits available in advance, and make rebuilds or replacements on all calipers in sets of two. To have the caliper, loosen the front wheel lug nuts, then lift the vehicle, and firmly set it on jackstands to have the front or rear wheels. Remove the banjo bolt from the caliper and remove the hose, and the sealing washers have to be discarded while the new one must be used further when tightening the banjo bolt. This should be done to avoid loss and or contamination of the interior of the hose by covering the end with a plastic bag. Remove the previous rubber dust boot from the caliper body and apply brake system cleaner to the surface to remove debris and dust. Check the thickness of the pad and replace when required. During the overhaul, place a piece of shop towels or wood on the caliper to avoid damaging on the piston when removing it using compressed air do not apply too much pressure when operate the air gun. Remove the dust boot in the caliper bore and retract the piston seal with wooden or plastic tool as not to mar them. Take out the bleeder screw and dispose the guide pin bushings and sleeves then, using the brake system cleaner, wipe all the rest parts and blow them dry. Check the piston and caliper bore for surface defects; if there is then replace the caliper. Clean brake fluid should be applied on a new piston seal before placing it in the cylinder groove after the dust boot has been implemented, piston should be fitted into the cylinder. Place the boot in the caliper counterbore, then mount the new guide pin boots and bushings and the bleeder screw should then be fitted. Slide the brake pads into the caliper and then fit the caliper and fasten the guide pin bolts. Join the brake hose employing new sealing washers and then tighten the banjo bolt. Evaculate the brake system, fit in the wheels and the nuts, lift the vehicle to a certain height and over torque the nuts. After the job precipitate the brake pedal several times to align the pads with the disc and then cautiously examine the brake before driving as usual.