1979 930

i have a 1979 930. the a/c system and compressor are basically "brand new". however, i think someone screwed up. a friend tested my system, and i have enough freon, but when the system is on, there is a vaccuum in the lines. he thinks the orifice tube is clogged up. where would this tube be located in the lines? any help is ALWAYS appreciated. much thanx.

chris <img border="0" alt="[cheers]" title="" src="graemlins/beerchug.gif" />

willard

The orifice tube is located just upstream of the evaporator.

But how is it your friend was able to do this test but yet couldn't tell you where the orifice tube is? Actual vacuum in a refrigerant system is highly unusual. with the system operating lower pressure, always, on the evaporator/orifice downstream side but not a vacuum.

1979 930

He hooked up the gauges to my compressor. it was late at night, but when the a/c was turned on, the pressure in the system changed to a negative (vaccuum) according to the gauges, which work flawlessly. he's unfamiliar with the porsche a/c setup (especially since this obviously isn't stock), and didn't know if he had to go under the car to find the orifice tube. i've worked on some a/c's before, but this one is new to me. i figure that the previous owner had the a/c done by a hack mechanic <img border="0" title="" alt="[Eek!]" src="eek.gif" /> who did the bare minimum of work...thank you for the info.

chris

upallnight

What type of compressor is in the porsche?

If it is the York compressor you need to back out the stem valve on the high side and low side in order to have the gauge read the pressure in the system.