Check your brake fluid lvl's. if its low or dry then you more than likely have a leak somewhere. You'll need help to find it. fill the master cylinder back up with brake fluid and then have your assistant get inside and pump the clutch and hold it while you bleed the clutch and look for leaks.
If by chance you don't know where the bleeder screw is on your Jeep...
On the 2.5 it should be under the Jeep on the right side of the transmission, just above the clutch hydraulic line. So just look for the line that can be traced back to the master cylinder.
When looking for the leak check the master cylinder, operating cylinder, and connecting lines. Lines should be easy to spot. I've blown a few b4. Also it could be as simple as the seal around the reservoir could be leaking.
Good luck and let me know if you get it fixed.