Thumb Lever or Mortise Lock Issue?

Question

I have a sliding glass door handle that appears to be 82-033. The locking lever sometimes slides down on its own thereby locking the door. Would replacing with the 82-033 be sufficient or do I need to replace the internal mortise assembly also?

Much obliged.

Bob · Accepted Answer

Thanks for posting. It certainly is possible the mortise lock is the cause of the problem here. If you remove the handle set and notice no damage to the thumb lever, then I'd wager the mortise lock needs to be replaced. We can help with this most likely; we just need to see a picture of it to help. Many thanks.