There are a few key signs that indicate that your brake drums and shoes need to be serviced. A common indicator is hearing squealing or scraping sounds when applying the brakes. The brake shoes will begin to squeal as they are wearing down. Once the shoe has completely worn out, the metal shoe platform that remains will create a metal-on-metal scraping sound. Brake shoes that have worn down to the metal can cause damage to your brake drums, requiring replacement.
Brake pedal feel is a strong indicator when determining the condition of your drum brakes. When brake shoes wear down, they are not able to firmly press against the drum creating an inconsistent pedal feel. If you feel vibrations when applying the brakes, it is time to inspect your drums and shoes and replace worn-out components accordingly.
A hard-to-pull hand brake or noticing your car roll back an inch or two after applying the hand brake on an incline can also point to trouble spots in the drum brake system. However, these symptoms can also point to a loose hand brake cable.
If you do replace your brake shoes, make sure you dispose of any hazardous waste safely. You can read more about disposing of old brake parts here.