I had a strange experience over the weekend...Friday leaving a state park while moving down a slow road...15-20 mph..my back wheels I think locked up ...I thought at first I had a flat tire by the loud sound and the way the jeep stopped ...no flat I tried to move forward ..wheels in back seemed locked...I turned the jeep off ...looked underneath again ..didn't see anything hanging down...started it back up and moved forward no problem...drove 25 miles home and drove it this weekend ...it has not happened again...It was raining very hard that day...wondering if that may have affected my brakes? ....any thoughts?

 

If you're not a DIYer and don't have much experience wrenching, I'd recommend bringing your jeep to a reputable shop and explaining your concern. They most likely won't be able to reproduce this problem if it's extremely intermittent but it's certainly strange and could potentially be dangerous to not only you but other drivers on the roadway.

 

^
What Jeepin' said.
If it happened once, its gonna happen again sooner or later...murphy's law.
Does your Jeep have ABS?