OP, how old are your pads? Are they "glazed over", have mud/dirt in them? What size tires are you running and have you recently went up in size tire? If you've upped your tire size then yes, you will see a loss in braking power, especially when the Jeep stalls. If the pads are glazed over they need to be changed. If they have mud or dirt caked in them you may need to clean or replace them also. I have the same problem as you. I'm running 37" tires and I feel my problem is the stock brakes aren't up to the task when on an incline and the Jeep stalls. However, I'm guilty of my first question in this paragraph. Before I go spend $1000 on new brakes, I may change out my pads to see if that helps. If it doesn't, I'm going to get the TF Big Brake kit or the new Dynatrac kit.

 

I run 37in double bead locks so they are very heavy. The pad could use a change I'm sure. I will change the pads and see but still don't know why the pedal is so hard. I bought a gauge to check the vacuum at the booster also.

 

Maybe the OP is under 80lbs?

 

That's a terrible problem to have. Glad it didn't go any worse. Hope you get it fixed.

 

Yup my first guess would be not enough vacuum. Probably a bad booster if the pedal is rock hard / not moving even after starting the vehicle back up which is what we had to deal with in my dad's old sedan

 

Brake booster checks out good. Pedal hardens up when pumped with jeep off then the gets soft when you start the jeep. On an incline however its hard no mater what. So hard you can't get the jeep to stop at all. And no I don't weigh 80lbs.

 

so it only happens on an incline then? Not when level or on a decline?

 

It's beginning to sound like when it's on an incline, the ABS module doesn't want to let brake fluid pass through.
Pull the ABS pump fuse J6, and the ABS valve fuse J7. See if it behaves differently.

 

I have done the abs kill switch mod and tried it with the abs killed and still didn't help. Would that be the same as pulling the fuses

 

My 07 acts exactly as you are describing. When I stall the pedal goes stiff and the Jeep will roll downhill some no matter how hard I stand on it. Once I turn the key the pedal goes back in and I have good brakes again. I'm interested in the ABS trick. Never heard of it before.