Mike,
I went back and checked the rotation of the piston. I went clockwise not CCW. Also, here's a quick how to I did for LLSOC:
This is my rear brake pad install. Your mileage may vary with this but this is how I did it. First things first! You'll need these tools to start.
This is not required but if you have one it's a little quicker to use.
Disc Brake Quiet by Permatex, 12mm open/box end wrench, 12mm socket and ratchet, flat head screw driver, Channel Lock Pliers.
Let's get started! The first thing to do is jack the car up and place jacks at the appropriate jacking points. SAFETY FIRST! Remove rear wheel and you're ready to go. First take out the 12mm bolts on the back side of the caliper.
Once you've taken the caliper bolts out you may have to use the flat head screw driver to gently pry the caliper from the rotor. Once the caliper is off you will notice the screw caliper piston with notches. Please take note of the position of the caliper piston notch. It will have to be in this position once you put it back on.
Take the old brake pads off and you'll notice the difference in the OEM pad and the Porterfield pad.
Before you install the brake pads you have to screw in the caliper so that it will fit over the new pads. You will need to make sure that the brake fluid reservoir cap is off because of back pressure. A local brake man here in town says you can buy the expensive caliper piston adjuster or just simply use a pair of channel lock pliers. I used the channel lock pliers to screw in the piston. When you begin to use the channel lock pliers be careful not to tear the rubber boot around the piston. Also, to screw it in turn the piston CLOCKWISE. As you turn the piston make sure you are applying pressure to the top of the piston to get it to compress. Take your time with this! Once the piston is completely compressed make sure one of the two notches lines up in the previous picture above. This is needed as a guide for the notch on the back of the brake pad.
Before you put the pads on add some of the Disc Brake Quiet compound on the back side of the pad. Please make sure this does not get on the surface of the pad that touches the rotor. After the application of the Disc Brake Quiet compound let it sit for minute so that it doesn't appear runny. Put the pads on the rotor. To replace the caliper simply replace it back over the pads and tighten the 12mm bolts. You're done! It took me about 1.5 hours to complete the rear pad install on both sides and clean up.
As before, if you have the rear caliper piston adjuster tool it make not take as long. However, as often as you may or may not change your rear brakes it might not justify to purchase one.