I will give an update on this issue so the next guy can learn from my ordeal..
The rebuilt caliper from O'Reily's was built with a right hand threaded piston shaft..It is supposed to be a LEFT hand theaded shaft...
After many dis-assembly/ re-assembly / bleeding/cycles thinking I missed something, I found a document on alldata that mentioned the left hand thread for the right side caliper...sure enough..Took caliper apart again and discovered a RH shaft on piston...Took caliper back to O'Reily's,,bench tested replacement caliper for LH shaft, re-installed and all is good now..
Lesson Learned..Just cause its rebuilt does not mean its done right.
Glad I caught this as I was starting to think ABS module was bad..$800.00 ouch..
Hope this helps someone down the road..