If replacement is necessary on this account then the calipers themselves should be replaced rather than overhauled; new and factory rebuilt are available on exchange. It is always good practice to replace the calipers in pair. To remove properly you have to start by loosening the wheel lug nuts, then lift the car, put it on jack stands and block the wheels at the other end before you can take off the wheel. It is followed by the removal of brake hose from the caliper by the removal of the inlet fitting bolt and removing the old sealing washers and fitted new ones and then the brake hose must be plugged so that no dust or air gets inside the brake system. When installing other components only, retaining the brake hose connected, suspend the caliper with the help of a wire only. After that, take out the caliper mounting bolts for inspecting the threads for damage, and if damaged, replace the bolts, and then unlock the caliper from the mounting bracket. For installation reverse the above said removal process and use new Sealing washers on both side of the brake hose inlet fitting, tighten the bolt of the fitting and the caliper mounting bolt to the torque value mentioned above. If the brake hose was disconnected bleed the brake system and check that there is no leakage from the hose joints and then take the brake on a very gentle test before putting it back to service.