Most sliding door lock problems start with alignment: a door that settled or a dirty track keeps the latch from seating. Cleaning the track, adjusting rollers and tightening the handle set solves many "it won't lock" complaints without new hardware.
The factory latch on many sliders is light-duty. A secondary lock — a security bar, track lock or keyed auxiliary lock — adds real resistance against lifting or forcing the panel.
When to replace
Cracked handle sets, stripped latch hooks or bent tracks call for replacement parts matched to your door brand. HSI Locksmith repairs and upgrades sliding door locks across South Florida.