1995 Jeep Cherokee

My Jeep seems to act incorrectly when I have a car full (4 people), but when it is just the driver or two it doesn't seem to do it. With a car full, when I am coming to a stop sign and I decelerate to around 30 mph it seems to chug in a way every one or two feet until finally stopped. However, I don't know if this is with the braking system or not, because it is not a grinding sound and I just had my brakes checked and worked on in the rear. Maybe it has something to deal with the wheels, I don't know. I just don't understand why it only does it with weight in the vehicle and not just with me and/or a passenger. Please let me know all the possibilities the malfunction could be, especially so I know what to tell my mechanic. Thank You.