You might find that your parking brake is not working like it should. This could be due to several things. The first thing I often check is the rear brake adjustment. Viewers often ask how to adjust their parking brake cable. I always tell them to adjust the rear brakes first, then see if they still need more adjustment for the parking brake. If you get the rear brakes adjusted and still don't have enough tension on the parking brake, then adjust the parking brake cable or adjuster, not before. If you adjust the cable without addressing the rear brakes, you might have issues installing the brake drum after a brake job because there's too much tension on the cable. If you have a parking brake problem, adjust the rear brakes first, then the parking brake cable.
In addition to adjustments, things can break. Mostly what I see is broken cables. This is what to look for if your parking brake suddenly stops working. Keep in mind you might have to remove some exhaust shielding in order to access the cables.
If your parking brake assembly is inside of the rear rotors, the adjustment is often accessed through the front of the rotor. Don't adjust these too tightly. If you do, you can overheat the brakes and cause other problems.