A coke oven hopper truck is movable along a coke oven cover which has therein filling holes closed by removable filling covers. The hopper truck has supported thereon a lifting device including an electromagnet which lifts and lowers the filling covers from and into the filling holes so that the filling covers may be removed from the filling holes, whereby coal may be charged through the filling holes into the coke oven chamber. The movable hopper truck has supported thereon repositories for supporting the filling covers after they have been removed from the filling holes by the lifting device. The repositories are movable with the hopper truck along the coke oven cover. The repositories have therein recesses dimensioned to receive therein the filling covers. Cleaning tools such as scrapers or brushes are provided along the edges of the recesses, and the lifting device rotates the filling covers against the cleaning tools to thereby clean the filling covers.