Door latch assembly systems as parts for land vehicles, namely, hydraulically-operated locks that secure debris tank doors on vacuum and hydrovac trucks, comprised of hydraulic door latches; door latch assembly system parts for land vehicles, namely, hydraulically-operated locks comprised of door sealing levers and mechanical linkages for holding the levers in a closed position; door sealing system as parts for land vehicles, comprising a debris tank in the nature of a vacuum tank being a str...