I replaced the compressor on my 2009 Impala last week.
Vacuumed the system, added 2oz PAG oil to the compressor and another 1oz to the line.
Recharged the system with R12-A using the conversion factor given to replace R-134A.
Worked nicely for a week but now no cooling. Getting a loud chattering noise under the dash when the A/C is turned on.
Getting 46psi static pressure on both high and low sides. With A/C compressor on getting 30psi low side and 65psi high side (75 F outside).
Any suggestions?