A dump truck is similar to other large, industrial vehicles in many ways, but it also features a few unique components of its own; while they may not all look exactly the same, dump trucks tend to share these specific components. Much like a flatbed truck, a dump truck features one axle underneath the cab and one, two, or three axles underneath the dump box, depending on the truck itself. A dump truck utilizes an internal combustion engine that is either powered by gasoline or diesel fuel, and the dump box is powered by hydraulics and features a tailgate that usually opens automatically during the dumping process.
Hydraulic Dumping 
A dump truck can relinquish its load in one of two ways: lifting or pushing. Although it requires more vertical clearance, lifting is the more popular method of dumping. In this case, the end of the dump box that is closest to the cab of the truck will be lifted using hydraulic pistons, which creates an angle and allows the contents of the dump truck to fall out. Dump trucks that use the pushing mechanism, on the other hand, rely on a vertical panel inside the dump box to push the contents of the box out through the tailgate.
Dump Truck Power
While the dump truck itself is powered in the same way as other gas or diesel trucks, the truck and the dumping mechanism both rely on the internal combustion engine. The transmission connects to the power take off, which powers the hydraulics; if the truck is off, the dumping mechanism cannot be used.