You need to apply LOCTITE GM P/N 12345382 (or equivalent) to the
Wheel Cylinder shoulder face which contacts the backing plate, spread the brake shoes apart, install the wheel cylinder, and the wheel cylinder bolts, then remove the cap from the brake pipe and install the brake pipe to the wheel cylinder, bleed the hydraulic brake system at the wheel cylinder, install the brake drum, install the tire and wheel, then lower the vehicle.