Does the pedal feels it grabs before it reaches bottom? If not, crawl under the Jeep on the driver side. You shoul dsee the Y connector there. Get a wrench, and adjust it until the pedal feels that it engages.
If the pedal feels like its grabbing, then adjust your brake shoes. Try first backing up and braking hard. If that does not do the trik, you may need to adjust them manually (again, not that hard).