stuck in 4 wd

I have a 86 jeep cherokee 2.5 slectatrac it went in fine but dont want to go back to 2 wd tried reverse tried drive and nothing fluid level is good also

I have a 91 that takes a lot to get out of 4wd. I have to go backwards and slam on the breaks violently to get it to disengage. there is probably a better solution to this probelm but i dont know it.
-JC

As you're driving back/forth try holding the 4WD selector down or slightly between selections. It might need adjusting. You could try pulling the vacuum line of the front axle or do I have that backwards? Is the vac. there to assist engaging or disengaging?

As you're driving back/forth try holding the 4WD selector down or slightly between selections. It might need adjusting. You could try pulling the vacuum line of the front axle or do I have that backwards? Is the vac. there to assist engaging or disengaging?
yes there is

The vacuum does both, engage and disengage. This is likely a vacuum problem. With the engine running and vehicle in Park, crawl under and pull the vacuum lines from the shifter motor on right front axle. Feel for vacuum. There should be vacuum on one of the lines in 2 wd and on the other line in 4 wd. You probably have a vacuum leak, or, as is even more common in a dusty climate, or in rough service, the vacuum lines become plugged. Another possibility is the switch on the transfer case. Remove the vacuum harness and blow it out, then reinstall it. May solve your problem. Less likely, but possible, is the vacuum shifter motor on the axle may be sludged, making it difficult to operate. You can remove it and clean it easily. While it is off, check the shifter collar for freedom of movement, and lubrication. Be sure when you reinstall the shifter motor you get the shifter fork onto the shift collar correctly.