Final answer:
The hydraulic pump is the component of a manual pallet jack used to raise the height of the load, applying pressure through an incompressible fluid to lift the forks.
Step-by-step explanation:
The component of a manual pallet jack that is used to raise the height of the load is the hydraulic pump. The hydraulic pump system works by applying pressure to an incompressible fluid, which creates the force needed to lift the pallet jack's forks and, consequently, the load placed on them. The handle-mounted control lever is often used to operate this hydraulic pump, whereas the forks are the part of the jack that slide under the pallet to lift it, and the steering wheels are used to maneuver the pallet jack once the load has been lifted.