Q: How to replace the rear parking brake shoes on a Mercury Grand Marquis?
A: Loosen the rear wheel lug nuts. Raise the rear of the vehicle and place it securely on jackstands. Remove the rear wheels. Remove the caliper and the Brake Disc. It's not necessary to disconnect the brake hose from the caliper; but hang the caliper out of the way with a piece of wire to prevent damage to the hose. Remove the axleshafts. Inspect the thickness of the lining material on the shoes. If the lining has worn down to 0.040 inch or less, the shoes must be replaced. Disconnect the rear Parking Brake Cable from the parking brake lever. Follow the accompanying photos for the parking Brake Shoe replacement procedure. Be sure to stay in order and read the caption under each illustration. Install the axleshaft and the brake disc. Temporarily thread three of the wheel lug nuts onto the studs to hold the disc in place. Remove the rubber access plug from the backside of the brake torque plate. Adjust the parking brake shoe clearance by turning the adjuster star wheel with a brake adjusting tool or screwdriver until the shoes contact the disc and the disc can't be turned. Back-off the adjuster eight notches, then install the hole plug. Install the Brake Caliper. Be sure to tighten the bolts. Install the wheel and tighten the lug nuts. To bed the shoes to the drum, drive the vehicle at approximately 30 mph on a dry, level road. Depress the parking brake pedal with about 20 pounds of force. Note: The vacuum release mechanism will prevent the parking brake from setting, if it is operating properly. Be sure to check the function of the vacuum release before performing the bedding-in procedure. Drive the vehicle for 1/4-mile with the parking brake applied like this. Repeat this procedure two or three times, allowing the brakes to cool between applications.