Chrysler Repair: 91 5th Ave.: AC noise, dryer filter, 5th ave

Question
Hello Roland and thanks for your assistance in advance.  I have 91 5th ave 3.3.  I had a compressor that went bad last year.  Replaced the compressor, all hoses, dryer, etc.  Recharged the unit with R12 as required.  Now on the smaller line, between the firewall and the compressor, after being engaged for at least 2-4 mins, the small line makes an increadible howl and vibration.  Its not constant, but comes and goes, and really is unusable because the noise is so loud.  The noise is coming from the smaller line between the firewall and the dryer/filter.  It seems to cool just fine, and the pressure is within range of what they specify in the manual.

Any suggestions apprecaited.

Thanks,
Chris

Answer
Hi Chris,
i don't find a symptom like that listed. I would suspect that a valve on either end of that smaller line might be getting 'arthritic' and thus vibrating and being amplified.   I would believe a local AC shop could diagnose that quickly. Please let me know when you find out for sure.
Roland