I just started getting really bad wheel hop when trying to stop. This is all new to me. What could it be. some times it dose it really bad other times it dose not. I can feel it though the brake peddle pushing back really hard.

 

Only through the brake pedal? Possibly a warped rotor (you may even be able to feel it with the front raised; if you spin the wheel and it drags at certain points but not others).

An actual hop of the whole truck? You might have lost a wheel balancing weight, or gotten a bulge in a tire (though you should feel those all the time). The bulge should be visible just by looking; the wheel weight is next-to-impossible to diagnose without machinery.

 

so driving around some more and stopping i think the back right is locking up and not opening back up. its about 20 degrees out side that side is kinda hot and has a very bad smell.