Intermitant go problem

I have a 2001 venture. Bought new. 55,000 miles. Had this problem 2 times where when van was put into reverse it was like the parking brake was on. Van did not want to go. Checked to make sure parking brake was released several times and it was. Shifted into neutral and park several times. Van would move (grudgingly) and the right rear of the van would raise up almost like I was running over an object with the right rear tire but nothing was under the van. The weather was also cold on both occasions. Any help would be greatly appreciated.

This one is a simple one. Your brakes are not disengaging when you release the parking brake. The cable or linkage to the rear drums may be rusty. With the van off, have someone sit in the van and work the parking brake while you crawl under the back of the van. You should see and hear the cable and rear drums moving and disengaging/reengaging as the pedal is set and released. It may only be the right side that is getting stuck though, so focus on the cable that heads that away first. Spray the exposed cable with some WD40 to try and loosen things up. If this doesn't work, you will need to remove the rear drums and inspect them for movement as before.