front air conditioner troubleshooting

[Dorn Hetzel]

I am trying to diagnose a non-functional front AC (the engine driven one).

The system does not seem to have any significant leaks, as it will
hold a vacuum when pumped down.

A local shop helped me add the conversion connectors so we could
connect the system to their diagnostic equipment.

After holding a vacuum on the system for 30 minutes, we added some
refrigerant and started up.

There is a very small amount of cooling generated, but high-side
pressure builds very high, up to 500 lbs, which leads me to guess that
there is a blockage somewhere on the high side before the expansion
valve.

So, we pumped the refrigerant back out and I took the bird home and I
am setting up to pump air through the various lines to see if and
where the flow is restricted.

I am trying to remove the high side line at the compressor, and there
are some clamps on hose, which I have loosened and pulled back, but
the hose still won't come off the barb fitting.

I am wondering if I am going to have to sacrifice that last couple
inches of the hose and cut it off, or if there is a better way?

Here is a link to a picture of the compressor and hose and with
retracted clamps. Any suggestions?

http://www.hetzel.org/2009-05-30-01-bb-02.jpg

Regards,

Dorn Hetzel
77FC35
Hogansville, GA