I don't know about a Dina, but I just removed all of the air locks from a MCI 102A3. All the air lock does is keep "unauthorized" people from opening the latches. The latches will stay latched while traveling down the road. Most of the older buses 4104, 4106, MC-7, MC-8, etc. had no locks from the factory, only a tab that a padlock could be used on. Hope this helps, Jack