I have a 1994 chevy blazer fullsize v8 , I have replaced condenser, accumulator, compressor, and orfice tube, I pull a vacuum no leaks, I can get one to one and a half cans in and when compressor is on the high side pressure just gets high over 400 psi I just shut it off, I am very frustrated and about to just take the ar-15 to the truck and get it over with! Need help please any information . Thanks