The most common problem is that very few adjust the shoe position to put them in the correct operating range of movement. The parking brake shoes adjust just like the old drum brake shoes did. There is a hole thru the wheel (don't even have to remove the wheel) where you use a screwdriver to rotate a "star wheel" adjuster. Up on one side to tighten, down on the other. When properly (or even close) adjusted you should only get three "clicks" on the parking brake pedal when applied and it won't get "forced" and "broke".
The Golden Rule
1984 300SD (bought new, sold it in 1988, bought it back 13 yrs. later)