Where is the "thread" on the piston for front brake calipers. Since you have to turn them in to make room for new pads, there must be a thread somewhere but (?)probably not on the side of the piston? Is there a screw mechanism that engages the parking brake or what? I can't visualize it and can't locate a website that gives a clear picture of the caliper broken down.

it threads into the back opf the piston, and is connected to the parking brake lever on the caliper. if you pull off the rubber boot you should see some of it..i think there is a pic in the haynes book

So, if I tried to change the pads without disconnecting the brake cable (even though the parking brake was not engaged) would that have any net effect on turning the piston in to make room for the new pads? Would the parking brake lever keep pushing the piston out as I was trying to turn it in? Have you changed pads without disconnecting the parking brake cable?

just take the cap off the reservoir and turn them things. they will go in if they turn. i have used the special tool and a pair of needle nosed pliars. works great either way. dont disconnect anything.