So I replaced the steering box on my 98 XJ with a Durango box and got it all back together and went out to take it for a test drive after attempting to bleed the system and the power steering works fine but there is a bad whine coming from the box and when I open the cap on the reservoir it has pressure in it and there are bubbles in te fluid which means there is air in the system. So how do I go about getting the air out?

 

You just turn the wheel lock to lock a whole bunch of times. That's all I've ever had to do

 

I haven't done it in a cherokee yet but usually these steps will do it:
1. Remove cap to power steering
2. Lift the front end up on jack stand & chock rear wheels
3. Turn wheel all the way to the left & hold for 3 seconds
4. Turn wheel all the way to the right & hold for 3 seconds
5. Repeat 3&4 until there is no air bubbles in the reservoir.

Good luck, could take awhile.