We have replaced the A/C compressor 3 times in the last 3 months. on 2004 GMC Yukon

We have replaced the compressor 3 times and the clutch n pulley keep breaking??? I have a certified mechanic working on it and he is baffled. Help!!! we have blown out all the lines and such and it last a week or so then shells out.

Asked by for the 2004 GMC Yukon
Has he flushed everything, changed the orifice and expansion valve. Is the condenser clear or restricted? Is the pressure switch working. Just trying to get a little more info.
the oriface has been changed and it was flushed out yes. yes it is clear and the pressure switch is working.
Where is it breaking, clutch hub bolt, pulley bearing hub breaking off compressor, how is it breaking.