If your parking brake isn't working correctly (not engaging enough or engaging too much), you'll need to take it to a mechanic. The problem is likely one of the following, requiring professional diagnosis and repair:
* Worn brake shoes: The brake shoes in the rear drum brakes are worn down and need replacement.
* Cable issues: Though not user-adjustable, the cable itself could be stretched, frayed, or broken.
* Internal components: There could be a problem with the mechanism within the rear drum brakes themselves.
* Adjuster mechanism: The automatic adjusters within the rear brakes might be malfunctioning and unable to compensate for wear.
Trying to adjust it yourself without proper knowledge can damage the brake system. Always have brake work done by a qualified mechanic to ensure safety and proper function.