As you did not give the year of your Caravan I can only reduce this to three choices.
The piston in the rear caliper on the 2008 Grand Caravan is the "screw in" type. A special tool is required to do the job.
It is called a 10MM aleen head sockit
a brake caliper tool (really)
With a scan tool.
With a scan tool.
You need the Dodge fuel line release tool.
With a scan tool.With a scan tool.
YesYes
Yes, the best one I have found for the price is Astro Pneumatic 7860 11-Piece Caliper and Brake Service Tool Kit. I bought it from Tooltopia. Do a search.
With an OBD2 scan tool.
A scan tool is required.
That requires a scan tool.