First introduced in 1958, the Chevrolet Impala 2004 model Impala came equipped with a base model 3.4-liter V-6 engine. A 3.8-liter V-6 and 3.8-liter supercharged V-6 were available in the LS and SS models. The brakes on the base model 2004 Impala are ventilated disc brakes in the front, and drum brakes in the rear. The 2004 Impala SS offered four-wheel disc brakes. Replacing the rotors on the 2004 Impala requires removal of all of the front brake components and someone with prior mechanical experience.
Open the hood of the Impala. Check the brake fluid level in the reservoir. Use a turkey baster or small bottle siphon to remove the brake fluid 1/2-inch below the "Full" mark. Loosen the front lug nuts with a tire iron. Raise the front of the Impala one corner at a time. Install jack stands beneath both front side frame rails, just inward from the lower control arms. Remove the front wheel lug nuts, then remove the front wheels.2
Insert a pry bar into the inspection hole in the center of the caliper body. Gently pry the inboard -- toward the engine -- brake pad away from the brake rotor. Remove the caliper bolts with a ratchet and socket. Remove the caliper from the brake assembly, using the pry bar if needed. Hang the caliper from the front strut spring, using a metal clothes hanger or thin metal rod. Remove the outboard brake pad from the caliper with the pry bar.3
Install a C-clamp around the inboard brake pad and the rear of the caliper body. Turn the C-clamp slowly to retract the caliper piston completely. Remove the C-clamp, then remove the rear brake pad with the pry bar.4
Remove the caliper mounting bracket bolts with a ratchet and socket. Remove the caliper bracket. Remove the brake rotor from the hub by hand once the caliper bracket is out of the way. Set the rotor out of your work area. Apply a thin layer of caliper grease onto the front face of the wheel hub, where it joins together with the brake rotor. Set the new rotor over the lug stems and onto the hub by hand. Spin one lug nut onto one of the lug stems to hold the brake rotor in place temporarily.5
Install the caliper bracket onto the brake assembly and tighten the bolts to 70 foot-pounds with a 1/2-inch drive torque wrench and socket. Install the new brake pads onto the caliper. Apply a thin layer of grease onto the backing plates on the brake pads. Push the outboard pad on until the tabs align with the indents of the caliper. Insert the inboard pad so the spring on the rear of the pad enters the center of the caliper bore. Install the caliper onto the caliper bracket and tighten the bolts to 44-foot-pounds with the torque wrench and a socket.6
Repeat steps 2 through 5 to replace the rotor and pads on the second side of the Impala. Remove the lug nuts from the faces of the new rotors, after you double check your torque on all of the brake bolts. Install the front wheels and snug the lug nuts with a tire iron. Raise the Impala off the jack stands, and remove the stands from beneath the car. Lower the car to the ground. Tighten the front wheel lug nuts to 100-foot-pounds with the torque wrench and a wheel nut socket.7
Enter the driver's seat of the Impala, and pump the brake pedal several times. If the brake pedal depresses to the floor of the vehicle more than twice, stop pumping the brakes and bleed the front brakes. Check the brake fluid reservoir level and fill if needed. Install the cap on the reservoir.