Either your emergency brake is hanging up or your wheel cylinder is leaking fluid and needs replaced if drum brakes and if disc brakes the caliper could be bad.
If you can't compress the piston with a C clamp back in to position to fit the new brake pads I would suggest replacing the caliper completely.
Brakes need adjusting? Pads need replacing? Caliper frozen? Low brake fluid level and need to be bled?
When replacing your brake pads on your Ford Explorer, you first need to jack up the vehicle and remove the tire. This will give you access to the brakes. Locate the caliper, remove the two bolts and slide the caliper off. Inside the calipers are the brake pads.
If you don't lube the caliper slide pins and pad slides, they'll bind. You'll get uneven pad wear
what is the best way to bleed brakes when installing new caliper on front left wheel
You will need to remove the tire and wheel from your 1986 Honda Accord. Remove the brake caliper and the brake spring. The disk brakes will come off. Reverse the process to install the new front disc brakes.
remove wheel, caliper,brakes,rotor. unplug abs connector and unbolt hub. install is reverse.
There should be no need to bleed the brakes after replacing the rear (or front) brake pads. Make sure you place a rag around the top of the fluid reservoir to catch any excess as you press the pistons back into the caliper body though. If the brake pedal has gone spongy after pad replacement this suggests that the piston seals have failed or the caliper cylinder facess have corroded. On mine the bleed nipples are on the caliper body.
The caliper is one part of the brake system.
Sounds like, at the very least, you damaged the caliper piston seals. The calipers will have to be replaced or rebuilt.
Remove wheel, remove caliper from mount, not from the brake line or the cable, get proper tool for working on rear disk brakes then twist the piston and compress it back into the caliper, install in reverse order.