yank on (someone or something)
To pull or tug at someone or something continually or with sudden force. The lifeguard yanked on the child to get him out of the water. Quit yanking on my arm like that! I kept yanking on the rebar, but I couldn't get it out of the cement.
yank on something
to pull or tug on something. Don't yank on my hair! Yank on this rope to send a signal to the worker on the floor above.