Leaking Mansfield 700 series sillcock

I have a 10 year old house and with a Mansfield 700 frost proof sillcock. When the water is ON, it leaks behind the handle, between the threads where the handle part of the valve screws in. Is there a repair kit for this valve? I can only seem to find one for the 500 series valves.

Thanks for your help.

Do you maybe need to tighten the packing nut that is on the end of the valve, between the handle and valve body? I like to have the water running a bit when I do this kind of tightening, just to take the pressure off the whole thing... I would think you would need replacement parts if it was leaking while the hose bibb is shut off.