Auto Air Conditioning & Heater Repair: RE. unusual ac system sound, direction arrow, vacuum pump

Question
Hi & thanks for reply
The low side pressure was about 40 psi at 2000rpm which I reduced it to about 30 psi at ýsame rpm and the sound was still present. The sound is like a whistle which takes place ýfor about 1 second and quickly stops. This is not continuous. Sometimes in the beginning ýof every run of the compressor the sound takes place and sometimes for about a quarter ýof time there is no sound. The sound is from about the environs the dashboard and is ýhearing through the blower hatches. I must mention that I also changed my dryer before ýcharging the Freon. He used a powerful vacuum pump. Is t possible that the problem be ýrelated to the Freon itself? ý
Thanks


Answer
The noise started after you replaced the drier and recharged the a/c. Thinking back,did you install the drier correctly? The filter can only be installed in a direction flow it is design for. There is direction arrow on the drier. Recheck the amount of freon recommended for your car. What country are you writing from? I`ll wait for your response.

good luck,davidt