1988 Pontiac Grand Prix

Brakes problem
1988 Pontiac Grand Prix 6 cyl Front Wheel Drive Automatic 180000 miles

I have done many a brake job. This is my first with rear wheel disc brakes. The book refers to this caliper as a " Type 15 Delco floating rear brake caliper". I have followed the books instructions, yet I can not get the piston to retract into it's bore. The book said rotate the piston clockwise if this problem comes up, but that was no help.
I took this job as a favor to a nieghbor lady, but now I can't get this fixed. This is her only car and I'm being more problem than good. I need this resolved ASAP.
February 20, 2008.

Remove the brake cable and the nut on the back, remove the seal, use a c-clamp or large channel lock pliers and push the piston back int the bore, if it will not go this way, replace calipers. And those big fat slide pins MUST be cleand and greased with silicone caliper grease. Remove the cover on the master cyl, and just place it over the master, before you begin.
To get the right adjustment on the rears, use a 14mmor 15mm, on the rear of the caliper and turn till the pads are touching the rotors. Replace seal, cable and lever. All done!

Feb 20, 2008.