Q: How to remove and install brake discs on a Mercury Mariner?
A: Loosen the wheel lug nuts, raise the vehicle and support it securely on jackstands. Remove the wheel and install the lug nuts to hold the disc in place against the hub flange. If the lug nuts don't contact the disc when screwed on all the way, install washers under them. Remove the Brake Caliper, suspending it out of the way with a piece of wire. If working on the front brakes, remove the caliper mounting bracket-to-steering knuckle bolts and detach the mounting bracket. Visually inspect the disc surface for score marks and other damage, checking both sides of the disc. If deep scoring is present, the disc should be removed and refinished by an automotive machine shop. To check disc run out, place a dial indicator at a point about 1/2-inch from the outer edge of the disc and turn the disc. The indicator reading should not exceed the specified allowable run out limit. If it does, the disc should be refinished. Regardless of the dial indicator reading, the discs should be resurfaced to ensure a smooth finish and a perfectly flat surface. If not resurfacing, remove the glaze from the surface with emery cloth or sandpaper. It's important to not machine the disc to a thickness under the specified minimum thickness, which is cast or stamped into the inside of the disc. The disc thickness can be checked with a micrometer. To remove the disc, remove the lug nuts and take the disc off the hub. To install, place the disc in position over the threaded studs. Install the caliper mounting bracket and caliper, tightening the bolts. Install the wheel, lower the vehicle, and tighten the lug nuts. Depress the brake pedal a few times to bring the Brake Pads into contact with the disc. Bleeding won't be necessary unless the brake hose was disconnected. Check the operation of the brakes carefully before driving the vehicle.