A: Never replace only one wheel cylinder-always replace both of them at the same time. Raise the rear of the vehicle and support it securely on jackstands. Block the front wheels to keep the vehicle from rolling. Remove the Brake Shoe assembly. Remove all dirt and foreign material from around the wheel cylinder. Unscrew the Brake Line fitting from the inner side of the brake backing plate. Use a flare nut wrench, if available, to prevent rounding off the corners of the fitting. Don't pull the brake line away from the wheel cylinder. Remove the wheel cylinder mounting bolts from the inner side of the brake backing plate. Detach the wheel cylinder from the brake backing plate and place it on a clean workbench. Immediately plug the brake line to prevent fluid loss and contamination. If the brake shoe linings are contaminated with brake fluid, install new brake shoes. Apply a thin coat of RTV sealant to the backing plate where the wheel cylinder seats, place the cylinder in position and install the mounting bolts. Connect the brake line and tighten the fitting, then lighten the wheel cylinder bolls. Install the brake shoe assembly. Bleed the brakes. Check brake operation before driving the vehicle in traffic.