The Mercury Grand Marquis is a luxury vehicle with a comfortable ride. According to Edmunds.com, the Grand Marquis "exhibits old-school automotive design with its stout but heavy body-on-frame construction, solid rear axle and softly tuned suspension calibrations." It is a heavy vehicle, which means that there is more wear on the brakes than there might otherwise be on other cars. When you begin hearing squealing while the brakes are engaged, it may be time to replace the brake pads. Replacing the brake pads offers you the opportunity to examine the rotors and replace them as well, if necessary.
Lift the end of your Grand Marquis with the brakes that need repair and remove the wheels. If both the front and rear ends of the car need replacement brakes, choose one end to start and complete all the steps there before tackling the other end. Use a tire iron to loosen the lug nuts on the wheels. Lift the end of the car with a floor jack and set the frame on jack stands. Remove the lug nuts and pull the wheels off.
Locate and remove the brake calipers. The calipers are U-shaped parts that grip the rotors on the exteriors of the wheel hubs. Hang a wire hanger from the frame of the car. Unbolt the calipers with a wrench and hang them from the wire hanger. Do not let the calipers dangle from the brake line, or the brake line may be damaged.
Remove the pads, anchor plates, the guide pins and the guide pin boots from the calipers. Examine the guide pins and boots for wear and replace them if they are worn. Reassemble the caliper assemblies with new anchor plates, bolts and new brake pads. Torque the bolts to 118 ft-lbs.
Examine the discs or rotors for cracks, gouges and unevenness between different areas. If there is damage or wear, pull the retention ring off and remove the rotor. Put a new rotor on and place a new retention ring on the rotor to hold it on.
Bolt the calipers back onto the wheel hubs and mount the wheels. Torque the lug nuts to 100 ft-lbs. Lower the car. Repeat steps 1 to 5 on the other side of the car, and on the other end if both front and rear brakes needed replacing.
