2002 Caravan Parking Brake Sound

I have a 2002 Caravan Sport, and recently the parking brake has starting making a sound. If the van is parked with the brake on, it makes a "thunking" (for lack of a better term) sound towards the back of the van when I
release the parking brake and take my foot off of the brake. Does anyone know what might be causing this sound?

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.