i didn't read your second post sorry.this would almost have to be an issue with the compressor valve plate[since you said that pressures were equal] this should be a gm round r4 compressor not known for being robust when used as a rebuilt.

__________________
David S Poole
European Performance
Dallas, TX
4696880422

"Fortune favors the prepared mind"
1987 Mercedes Benz 420SEL
1988 Mercedes Benz 300TE (With new evaporator)
2000 Mercedes Benz C280
http://www.w108.org/gallery/albums/A...1159.thumb.jpg