The two main areas to investigate are dock leveler weather seals and overhead door dock seals. Many dock leveler installations have conventional weather seal installed at the top of the deck side plates. This weather seal provides the best seal with the dock leveler in the closed stored position. When the dock leveler is on the truck bed and the truck bed is higher than finished floor, this sealing effect is lost. A number of dock leveler manufacturers offer a secondary wedge seal design to seal the dock position when the dock leveler is in use on the truck. If the loading dock area has compression dock seals and light is evident at the sides and top of the seal with the truck in position there is room for improvement.