Auto Air Conditioning & Heater Repair: A/C compressor of plugged line problem?, orifice tube, vacuum pump

Question
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Followup To
Question -
Thanks in advance for your time.  My 1997 chev k1500 pick-up's A/C compressor is making a loud clicking noise only when the A/C is on. It does not blow cold air and the low side pressure is approx. 150lbs. (very high)  I had an auto shop hook up their diagnostic machine and they said either the compressor is shot or there is a plugged line since there is not any change in air pressure (hooked up both the high side and the low side lines to the machine) when the A/C is turned on or at all. I would hate to replace the compressor if it is only a plugged line.  Does any of the indicators give a clue to whether it would be the compressor vs a plugged line?
Thanks for your help (especially since this weeks temp. has been over 100 degrees.)

Mike
Answer -
I would suspect a restriction in the orifice tube (expansion valve) rather than the compressor.

Thank you for the quick answer!  Do you have any tips on fixing this or ways for me to check to see if this is the problem?   Thanks again for your time.
Mike

Answer
The orifice tube can only be checked VISUALLY. So you will have to discharge all the freon and physically remove the orifice tube and I would replace it.

Then you have to evacuate all the air from the system using a vacuum pump and then recharge the system with freon.