Parking Brakes loud stroke after releasing

If you park with the rotors wet they will often "corrode" to the pads, making a "bang" sound when you next start to move (next morning). It takes a few hours for them to stick. If it did this when it was raining, and now it isn't raining, that would explain it.

 

Yes, uneven ground will cause the car to pitch a bit when setting or releasing the parking brake, in my experience. The bang may have been the pawl that freezes the transaxle in place when set to P.

 

How many miles on it, and have you ever had the rear brake maintenance done, ie: caliper pulled off, pad/shim inspection and clean up, caliper pin lubrication? And if so how recently, and who did it?

A couple of things you can try to just check on their general condition:

1. Feel the rear wheels after an extended drive. If they're hot the brakes are dragging.
2. More-or-less the same but more definitive: chock the front wheels, release parking brake and raise the rear end (easiest with a floor jack at the rear central jacking point), and try spinning the wheels. They should easily spin a revolution or two, with only minor drag, due to the disc brake configuration. If they're really fighting you something is awry.

 

"pawl" is something internal to the transaxle (aka transmission), basically a pin that stops rotation, prevents the front wheels from turning. It's activated whenever you turn off the car or push the "P" (Park) button.

 

If there is any forward or rearward force on the car with the parking brake applied, the rear suspension should move up or down a bit. When you release the brake it returns to "normal".