Make sure the cap is off of the brake master cylinder. You can use a tool designed to move the caliper or a c-clamp. If the piston is too far out it may not go back into the caliper.
I have a 2004 TSX and learned the hard way how to change the rear brakes and had to buy a rebuilt caliper for my mistake. Most brake calipers compress with a simple C-clamp to make room for the larger/newer brake pads. The rear brakes on a TSX are different and you'll notice they have a couple of grooves on the caliper piston. They make a tool that is sold at AutoZone that allows you to compress the caliper piston by rotating it clockwise back into the piston. (It looks like a metal cube with metal prongs sticking out) I also recommend using brake grease on the exposed caliper piston boot prior to compressing it as this will allow the piston to rotate without damaging the boot. Don't forget to bleed the brakes afterward since rotating the piston will likely allow some air into the brake caliper.
be sure to purcahse the tool to "screw" the caliper piston in. If you try to push the piston in on rear disc brakes you will damange the caliper.
19mm deep socket for wheelnuts, 7mm Allen wrench to remove caliper bolts, 8" c clamp to push piston back into caliper housing
It is a tool to reset the piston on rear discs brakes
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.
the piston needs to be turned counter clock wise while compressing the piston
The best thing you can do is replace the caliper.
Whoever replaced your pads may have neglected to apply anti squeal goop to the back of the new brake pads. Brake pads should have some greasy stuff smeared on their surfaces where they meet the caliper, the caliper piston, and at the ends where they fit into the caliper. The squeal is caused by high frequency vibration where the back of the pad presses against the caliper and caliper piston(s).
The piston is forced out of the caliper by the pressure of the brake fluid. This pushes the brake pads against the rotor, in turn stopping the vehicle.
Yes
Remove caliper mounting bolts Slide caliper off rotor Use a "C" clamp to fully retract piston into caliper body If parking brake is used on this caliper piston is threaded and a special tool (not expensive) is required to thread piston into caliper body
Disk brakes by design do not have adjustments - the pads 'float' with the caliper and the piston movement.