Kelly, a picture of the plant would be really helpful. It is probably natural for a transplanted tree to lose some older leaves, especially if you had to root-prune it. In fact, it might have been a good idea to take some of the foliage off proportionally when you did the move. i.e. if you removed, say, 1/4 of the roots, you should take off 1/4 of the leaves too.
How long ago did you move this plant? After all, it IS July and about as hot as it gets in the next month or so. It would have been much easier on the plant to move it in the fall, or during the cold weather when it was more or less dormant. So . . the transplant shock is really setting in now that the weather is so hot.
If you are seeing any new growth at the top, you could give it some VERY dilute fertilizer. If you're not seeing new growth, it's still trying to grow roots and doesn't need much other than water. Is there any way you can rig up some shade for the tree? A piece of shade cloth suspended over it, or something similar?
Have you mulched over the roots? A thick layer of organic mulch like wood chips will help retain moisture, as well as protecting the root area from the direct sun so the roots will be cooler. Don't ever use rock or rubber mulch, as it doesn't insulate, and heats up in the sun, instead of absorbing some moisture and staying cooler.