Answer: Having proper working drum brakes is essential to operating a safe vehicle. If you have worn drum brakes, operating your vehicle can be very dangerous. There are many parts to a drum brake and since there are many parts, there are several things that need to be checked to make sure a drum brake is working properly. The brake shoes need to be checked for excessive wear so they don’t damage the drum. The brake drums need to be checked for excessive wear or cracks. They also have to be machined smooth when a brake shoe is replaced and can only be machined down so far, then they must be replaced. The required diameter is inscribed on the drum. Wheel or brake cylinders need to be inspected for any signs of leaking. The return springs need to be checked because if they are too worn and don’t return the brake shoes back to their original position, away from the drum, the brake shoes can experience rapid and excessive wear. Finally, the self-adjusting system must be inspected to make sure it is clean and properly lubricated.